overheating and speedo not functioning

96 3100 I notice that there are many posts on here relating to both these topics.
I decided that I am going to flush the system tomorrow and replace the thermostat then when I get a chance to pick up a PCM and VSS from my local pull it yard I will swap those out as well.. and pray this resolves the issue.. the car was abandoned in my yard a year ago finally got it transfered over legally and put a few bucks into it to get it running.. many issues but not completely trouble free.. so once i get past these couple of issue should be okay for a couple of years.. any input or suggestions on these particular topics feel free to hit me up on your thoughts.. any other ideas outside of drilling 2 holes in the thermostat? I would be interested in working past these 2 minor issues that could cost me an engine.. oh btw there are no codes thrown on this after replacing the spark plugs and battery which threw codes prior to replacing and now no codes just runs towards the hot line and the speedo does not work I havent had in out on the highway to test the cruise so i cant say if that works or not.. thanks for any help.. Linda

Given the weather you've experienced this past winter, I'd suggest that you not drill any weep holes in the thermostat. If you fill the system properly and use the two bleeders to purge air from the system there should be no problems with a standard thermostat. Weep holes will slow the warmup of the engine, even with electric fans, and may prevent reaching adequate temperature in colder weather.

The VSS or PCM could be an issue, but other things are required for the speedo to operate. The digital speedo module is powered by Fuse 15, so make sure that is intact. If the cruise operates and transmission shifts normally, the VSS is probably operating. The electrical connectors on the instrument cluster are also suspect.

Given the weather you've experienced this past winter, I'd suggest that you not drill any weep holes in the thermostat. If you fill the system properly and use the two bleeders to purge air from the system there should be no problems with a standard thermostat. Weep holes will slow the warmup of the engine, even with electric fans, and may prevent reaching adequate temperature in colder weather.

The VSS or PCM could be an issue, but other things are required for the speedo to operate. The digital speedo module is powered by Fuse 15, so make sure that is intact. If the cruise operates and transmission shifts normally, the VSS is probably operating. The electrical connectors on the instrument cluster are also suspect.
ok thank you for your reply. since this vehicle is new to me.. please let me know where the bleeder are located to burp this baby.. thank you again.. and if you know where the PCM is located I am going to u pull it tomorrow to find items.. thanks again
LAD

Given the weather you've experienced this past winter, I'd suggest that you not drill any weep holes in the thermostat. If you fill the system properly and use the two bleeders to purge air from the system there should be no problems with a standard thermostat. Weep holes will slow the warmup of the engine, even with electric fans, and may prevent reaching adequate temperature in colder weather.

The VSS or PCM could be an issue, but other things are required for the speedo to operate. The digital speedo module is powered by Fuse 15, so make sure that is intact. If the cruise operates and transmission shifts normally, the VSS is probably operating. The electrical connectors on the instrument cluster are also suspect.
ok thank you for your reply. since this vehicle is new to me.. please let me know where the bleeder are located to burp this baby.. thank you again.. and if you know where the PCM is located I am going to u pull it tomorrow to find items.. thanks again
as for the tranny all works well with that .. no cruise on this vehicle.. I will check the fuse and replace..to be safee and post back here to inform.. again thanks
LAD

bleeders:

1 on top of the black pipe comeing out top of the water pump, need 8mm socket
2 follow the driver side rad hose into the engine and have a slotted screwdriver in hand


both are brass, just snug them back. id park on an incline with the front end of the car higher than the rear, gently pat hood to encourage burping

bleeders:

1 on top of the black pipe comeing out top of the water pump, need 8mm socket
2 follow the driver side rad hose into the engine and have a slotted screwdriver in hand


both are brass, just snug them back. id park on an incline with the front end of the car higher than the rear, gently pat hood to encourage burping
thank you Kevin will get on the radiator issue tomorrow..

anyone want to help me locate the PCM on this model please join in ..

well while testing the cooling issue my brake light went on .. master was completely empty .. blown wheel cylinder i presume, I will watch that and if it empties again figure i need a new wheel cylinder somewhere..

but anyway the cooling system now appears to be cooling.. although it still is throwing bubbles up into the overflow.. not sure if this is a normal thing with this vehicle.. but it is not loosing coolant and appears to be holding temp just over the half way point so i think we are safe for now on the cooling system..

LAST BUT NOT LEAST:

Still have to locate that PCM.. or figure why my speedometer is not recording milage or speed... trip isnt working either, if it helps I do hear a noise that sounds like it should be registering but then again with everything behind the cluster it is hard to tell what actually is making the noise like a plastic spinning wheel back there..
i took the dash appart and nothing appears to be off behind that.. all connected and no broken, cracked or rusty wires.. Fuse 15 is my HVAC.. and nothing there to indicate speedometer.. under that falls under "other instritment"

i did pull every last one of my fuses..in all 3 panels.. found something interesting.. i have a wire running up into the DS engine fuse compartment which has a 30 amp large fuse which was snaped in half.. not the metal that was still in tact..?STRANGE? but the plastic casing was snapped I replaced it anyway to be on the safe side .. does not appear to have changed anything on the way it functions.. it is not labeled so i have no clue what it is for.. ..LOL

oh well I will post a new thread for my speedo issue seperate now.. i am gonna make a run to the u pull it later today so i would like to know where to locate it so i can pull one and test it out.. thank you for all you help...
LAD

an endless supply of bubbles can be a leaking head gasket.... compressed fuel/air from cylinder leaks into the water jacket during compression stroke.

the ECM is hiding on top of your passenger side wheel well under a black plastic cover, two metal buckles and the cover should come off. you'll also notice the very large black wire conduits leading to it. right in front of the overflow tank.


im clueless about the speedo. but i think if your cruise work, then its a problem wtih the instrument cluster or wiring to it. maybe if one of the other vets can chime in as to whether the transmission needs the VSS to control shifting, you could at least use that info to see if the VSS is the issue or something else.... ive never had to touch anything speedo or cruise control related on the lumina.

an endless supply of bubbles can be a leaking head gasket.... compressed fuel/air from cylinder leaks into the water jacket during compression stroke.

the ECM is hiding on top of your passenger side wheel well under a black plastic cover, two metal buckles and the cover should come off. you'll also notice the very large black wire conduits leading to it. right in front of the overflow tank.


im clueless about the speedo. but i think if your cruise work, then its a problem wtih the instrument cluster or wiring to it. maybe if one of the other vets can chime in as to whether the transmission needs the VSS to control shifting, you could at least use that info to see if the VSS is the issue or something else.... ive never had to touch anything speedo or cruise control related on the lumina.

Kevin thank you for your reply I will work on this a bit more tomorrow..
IS the ECM the same as the PCM? I know ECM is engine contol module.. is PCM Power control module and are they the same thing??
Also VSS and TSS variable speed sensor and transmission speed sensor.. but are they the same thing?

I hate the sensors and junk on cars today with the side mount engines... give me a 1960 or 1970 vehicle any day.. plenty of room, no cut knuckles, simple to diagnose and fix.. LOL

i am going to work this way from least cost to most..

I did notice along the back manifold sides that there appears to be slight leakage.. seeping.. could be worse in the center back where i can not visually see due to location. a gasket would be timely but cheap.. unless the block is warped or cracked..

the over flow bubbles and even after burping the air out.. it is sucking in air from somewhere.. I think maybe I should replace the gasket first.. and do a flush before the sensor and thermostat ...?????

I can get the sensor and thermostat and water pump each for under 20.00 the radiator i can get new for about 89.00
so I am going to go with replacing the sensor and the thermostat and include a flush.. if the gasket doesnt fix it

if that does not help I was going to go to the water pump next and then replace the radiator even though there is no evidence of any water in those areas..


I have no tools to measure and check this stuff with the head gasket should I just go ahead and replace and see if that makes it better or worse?

the only thing with this is there is no water in the oil and no oil in the water.. oh waite that would be an internal leak ... this is external which is far better.. ah maybe when i get a few more bucks I will do the gasket before replacing the water pump and the radiator since there is no indication any water is coming out of them.


I can get a pressure check for 13.00 locally.. when you get a pressure check do they tell you specifically where the problem is? or do they just tell you if it is internal or external? should i spend the money here or just replace and repair as the order i outlined?

as for the speedo.. the bottom conclusion is everyone i have spoken with says it is the cluster that is the culprit... since it is highly not likely that it is anything else.. it has no cruise on this model.. so 25.00 and I pull it gets the speedo fixed i hope..

VSS - if you are shifting still, probably is the instrument cluster. otherwise youd be stuck in 1st gear i believe, like B-bowtie said earlier... agree probably issue in the cluster. you MIGHT get lucky and pull the cluster out, clean the contacts, reinstall connectors and check see if speedo works before you put it back together. dash bezel doesnt come out easily, if tilt steering, drop the steering wheel to lowest position, you'll have to bend the bezel slightly. bezel retaining clips fall off easily.

you probably have a failing intake gasket at the outside edge, so coolant is escaping - see my pic in thread i linked below - you probably have gasket failure at one end of the intake gasket, where coolant escapes/seeps externally. after engine cooldown, slight suction in cooling system is sucking in air from this leak. its easier to suck in air from the leak, than to suck coolant from the reservoir pass the rad cap.

skip rad replacement. its probably pretty junked up with sludge but a professional flush will help lots. if they sold the big O-ring on the plastic tanks on the rad, i'd have already removed the rad, opened it up and cleaned it out by hand. probably runs a bit hot with the sludge

head gasket probably ok, (its a low mileage car isnt it?) i replaced mine b/c i wanted to rebuild the heads. the old head gaskets looked pretty "soggy" bloated looking aroudn the cooling passages.

pressure check? on cooling system? assume you not talking about compression pressure check. it will probably tell you what you already know... leaky LIM gasket. they will just tell you have a slight pressure loss, not where it's at.


ECM/PCM

i use both terms. same thing, almost. PCM is really only for automatic transmissions (PCM = ECM + TCM). If you have a manual transmission then it's basically an ECM since there is no tranmission controller.

other confusing terms, not all apply to the lumina, or at least i havent run across them yet thankfully:

wss - wheel speed sensor - probably term used in conjunction with 4 wheel abs? Anyway, measure wheel rotation.
vss - vehicle speed sensor - sensor at TAIL shaft of transmission, basically how fast you are moving
tss - turbine shaft/speed sensor (measures the transmission INPUT shaft speed to determine amount of slippage from the torque converter. not sure if we have one of these on the lumina. remember torque converter always slips a little until TCC engages. NOT used to determine vehicle speed.
tcc - torque converter clutch. locks up torque converter at cruise for better mpg.

long time ago. i was in that "i hate all these fancy computer crap on cars" but have embraced it and fairly understand it. i was into hobby electronics before computers were the in-thing, made it that much easier.

not a fan of these side mount engines either, it just seems WRONG. no space to work, have to remove 5 unrelated parts to get to the part you need to replace. my dodge ram on the otherhand, i could fit a couple of bodies under the hood..

---

to address the seepage.
cant have coolant seepage from side of engine unless its coming from head gasket.

there are 6 seals on each lower intake gasket:
see pic
http://www.automotiveforums.com/vbulletin/showpost.php?p=6374105&postcount=56

see pic of old intake gasket with arrows. the 3 big openings are INTAKE. the two edge openings are COOLANT.

3 orange seals between each intake runner and the crankcase oil. impossible for these intake seals to pull in coolant unless coolant is in the oil
2 orange seals for the coolant passages that goe into the intake. leak causes oil/coolant to intermix (oil leaks in cooling system on engine cooldown, while engine running, coolant forces itself into engine crankcase and mixes with oil) also cause external coolant leak and definitely air leak INTO cooling system.
1 black plastic all around generally seals the crankcase from open air.

if you look at the LIM gasket pic with the 2 arrows - that arrow on left shows where i had coolant almost POURING out onto the ground (external leak) AND some leaking into crankcase. middle arrow pointing at intake runner, shows where i probably had oil (and crankcase air) sucked into the combustion chamber of #3 or #4 cylinder (vacuum leak)

lower intake gasket failure causes one or more of the following:
1) external coolant seepage at front or back of engine.
2) internal coolant seepage into lifter valley and into engine oil. slight chance to suck in oil into cooling system during engine cooldown.

head gasket leak:
1) leak coolant into combustion chamber, and lots of air (fuel/air/combustion gas) into the cooling system
2) oil into combustion chamber
3) oil/coolant intermix
4) air leak between adjacent cylinders (low compression on 2 adjacent cylinders )

engine running, engine hot: oil is 40psi, coolant is 15psi. this is when oil can get into cooling system
engine off, engine cooling: oil is 0psi, coolant goes from 15psi to a "slight vacuum". this is when coolant can get into oil when cooling system is still pressurized, and suck in oil into cooling system when engine is cool and slight vacuum in cooling system



bubbles - since you dont have the steady stream of bubbles [indicating head gasket leak] then you are getting your air when the car cools - when there is a slight suction in the cooling system, leaky intake gasket sucks in air - instead of the rad cap sucking in coolant from coolant reservior. this air causes dexcool to sludge.

consider ordering parts online... like rockauto. that is where i got most of my parts for my top end rebuild.

Thanks Kevin I already ordered a head gasket set on ebay for 65.00 last week and got them friday after noon great price since locally it would have cost double that for just the intake gasket.. spent most of yesterday afternoon pulling the valve cover and junk off to the intake manifold.
I was pretty certain I was looking at the intake being the issue although my mechanic thought it was the water pump.. I still get some bubbly in the reserve tank but just slight bubbly... there was a part of the intake gasket missing in on driver side and a run mark idicating it was there for a while also on passenger side there was pooling and the gasket was soft and not tight the bolt where there was pooling was only hand tight? dont know why of how that would loosen over time and hard to believe that it would be put in there without being tighten at all we didnt even need a wrench to remove it!!!
.. the top of the valve cover had 'pudding' on it my mechanic then thought it may be the head gasket. but i pointed out that the lifters and valves were looking clear dark and fine so he then agreed that it was most likely just the intake gasket.. I have always been told that if the head gasket is done in that the water will have oil mixed in and the oil will look like chocolate pudding. just like what we saw on the valve cover inside.
After putting it back together ended up with a cracked clip which we had to rig up to get by.. and a crack in the trans line in front of the radiator which I will need to replace this week but rigged that with rubber hose for now so it doesnt leak.. plus ended up with a rear drum seal popped so have to replace that as well

I will mess around with the cluster tomorrow before going to U pull it and see if i can clean contacts to get it working or just replace it with another part .. crossing fingers that after this the lumina will give me a break from repairs for a few months.. although it isnt looking that way.. fix one problem get 2 more to work on.. LOL
I usually end up with a bolt or nut left over but I ended up short a bolt and a nut this time.. I still cant figure out who ate them for lunch..:runaround:

head gasket probably ok, (its a low mileage car isnt it?) i replaced mine b/c i wanted to rebuild the heads. the old head gaskets looked pretty "soggy" bloated looking aroudn the cooling passages.

pressure check? on cooling system? assume you not talking about compression pressure check. it will probably tell you what you already know... leaky LIM gasket. they will just tell you have a slight pressure loss, not where it's at.


ECM/PCM

i use both terms. same thing, almost. PCM is really only for automatic transmissions (PCM = ECM + TCM). If you have a manual transmission then it's basically an ECM since there is no tranmission controller.

other confusing terms, not all apply to the lumina, or at least i havent run across them yet thankfully:

wss - wheel speed sensor - probably term used in conjunction with 4 wheel abs? Anyway, measure wheel rotation.
vss - vehicle speed sensor - sensor at TAIL shaft of transmission, basically how fast you are moving
tss - turbine shaft/speed sensor (measures the transmission INPUT shaft speed to determine amount of slippage from the torque converter. not sure if we have one of these on the lumina. remember torque converter always slips a little until TCC engages. NOT used to determine vehicle speed.
tcc - torque converter clutch. locks up torque converter at cruise for better mpg.

long time ago. i was in that "i hate all these fancy computer crap on cars" but have embraced it and fairly understand it. i was into hobby electronics before computers were the in-thing, made it that much easier.

not a fan of these side mount engines either, it just seems WRONG. no space to work, have to remove 5 unrelated parts to get to the part you need to replace. my dodge ram on the otherhand, i could fit a couple of bodies under the hood..

---

to address the seepage.
cant have coolant seepage from side of engine unless its coming from head gasket.

there are 6 seals on each lower intake gasket:
see pic
http://www.automotiveforums.com/vbulletin/showpost.php?p=6374105&postcount=56

see pic of old intake gasket with arrows. the 3 big openings are INTAKE. the two edge openings are COOLANT.

3 orange seals between each intake runner and the crankcase oil. impossible for these intake seals to pull in coolant unless coolant is in the oil
2 orange seals for the coolant passages that goe into the intake. leak causes oil/coolant to intermix (oil leaks in cooling system on engine cooldown, while engine running, coolant forces itself into engine crankcase and mixes with oil) also cause external coolant leak and definitely air leak INTO cooling system.
1 black plastic all around generally seals the crankcase from open air.

if you look at the LIM gasket pic with the 2 arrows - that arrow on left shows where i had coolant almost POURING out onto the ground (external leak) AND some leaking into crankcase. middle arrow pointing at intake runner, shows where i probably had oil (and crankcase air) sucked into the combustion chamber of #3 or #4 cylinder (vacuum leak)

lower intake gasket failure causes one or more of the following:
1) external coolant seepage at front or back of engine.
2) internal coolant seepage into lifter valley and into engine oil. slight chance to suck in oil into cooling system during engine cooldown.

head gasket leak:
1) leak coolant into combustion chamber, and lots of air (fuel/air/combustion gas) into the cooling system
2) oil into combustion chamber
3) oil/coolant intermix
4) air leak between adjacent cylinders (low compression on 2 adjacent cylinders )

engine running, engine hot: oil is 40psi, coolant is 15psi. this is when oil can get into cooling system
engine off, engine cooling: oil is 0psi, coolant goes from 15psi to a "slight vacuum". this is when coolant can get into oil when cooling system is still pressurized, and suck in oil into cooling system when engine is cool and slight vacuum in cooling system


bubbles - since you dont have the steady stream of bubbles [indicating head gasket leak] then you are getting your air when the car cools - when there is a slight suction in the cooling system, leaky intake gasket sucks in air - instead of the rad cap sucking in coolant from coolant reservior. this air causes dexcool to sludge.

To answer your questions.. Low miles hell no the speedo stopped at 188,119.. It was left to me in leu of payment and certainly not worth what was owed me since it cost me over 500 so far to fix no cost for labor either since i have been investing my labor,, plus the car was mostly in NY which means the undercarriage is rusting big time ... make this a non profit venture.. LOL but of course..the car has limited lifetime left but it may get a couple more years before biting the big one..

I bypassed the pressure test at autozone figured it was LIM..

Image 7 of 8 is where i had my intake gasket ripped a chunk out of it completely and it was leaking which is what i beleive caused the sludge on the valve cover.. at least i hope it was the reason and not the head gasket...

Kevin thank you for clearing up all my questions who knows possibly I will get used to this new world of sensors.. although I am reluctant to learning it.. I am computer savy,, but still all in all, I would like the old engines mounted in the 'RIGHT' way,, with room to move and bust a nut when you need to and not your knuckles.. I still have much to learn and at my age and with the mess my back is in.. I should not even be doing any of this.. but hey someone needs to teach my young men, so i wont have to do this much longer...:naughty:

intake bolts were not loctite'd at the factory so they can work loose over time.


i wound up only missing one of the short bolts that fasten the exhaust manifold heat shields.... acceptable loss.

my lumina is still running great!

ok back to the drawing board on this mess..
there is diffinately a short in the dash,, the speedo now clocks miles while sitting still when you turn on the stereo the trip puts miles on standing still..
LOL
coolest thing I have ever seen but still no good..
the radiator overheats after 5 minutes in drive,, not sitting park only in drive and once it over heats sitting in park just makes it worse..
I was told that bleeding it while running is improper proceedure that it needs to be cold and the bleeders open when topping up .. then replace cap and run engine til T stat opens then remove cap and top off and close again .. so I am gonna try that tomorrow and if it doesnt fix it chance on the T stat being bad and replace that and hope that works..

I may start another thread on this as the problems seems to be shifting in a different direction: Here is the reason:
After replacing the LIM gasket, thermostat with a fail safe, tempted to replace water pump.. but I sat there staring at the car while it was running.. here are pictures of my concern:
<bR><a href="http://s262.photobucket.com/albums/ii116/personlyplus/Mobile%20Uploads/?action=view&current=0826000855.jpg"; target="_blank"><img src="http://i262.photobucket.com/albums/ii116/personlyplus/Mobile%20Uploads/0826000855.jpg"; border="0" alt="Photobucket"></a><BR>
<a href="http://s262.photobucket.com/albums/ii116/personlyplus/Mobile%20Uploads/?action=view&current=0826000854.jpg"; target="_blank"><img src="http://i262.photobucket.com/albums/ii116/personlyplus/Mobile%20Uploads/0826000854.jpg"; border="0" alt="Photobucket"></a><BR> I have noticed that 2 main wires have major melting on them. I am concerned that this may have somethign to do with the stereo and speedo not working the way they opt to and the radiator overheating even though I have taken the normal steps to resolve the issue. I dont think I am going to win with this vehicle until I address this issue first..
Does anyone know if a short or several shorts in the electrical system can cause all these other issues without throwing any CEL codes?? thank you in advance.. Linda