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i think i have a problem...


PunkAlex
01-02-2004, 05:17 PM
I was working on my engine today, and usually i can get it started with no problem, but it wasnt driven for about 5 months. WEll yesterday i got my arse in gear and got everything working. So i was driving it today and the clutch went out, just sorta started slipping completely and i revved the motor pretty high, and it let out two loud backfires. Well after that it would crank, but not start. I took off the oil pan and none of the rods look bent, but when i took off the cylinder head, there was oil on the piston head. What exactly does that mean? I checked the piston and there are no visual holes. I also put new oil in it today, if that could mean anything. Thanks for your time.

MustangRoadRacer
01-03-2004, 07:33 AM
oil could be from when you removed the head, I doubt the oil would still be in liquid form if it made it's way into the combustion chamber.
sounds like the clutch/flyeheel. if the flywheel was damaged, the engine will not turn over. check under the car, where the starter teeth engage the flywheel. If the flywheel is being engaged, then do the universal "car no start" check.
Step 1. check for spark.
Step 2. check for fuel delivery (backfires can break a carb).
Step 3. check compression.
let me know how things go. good luck.

PunkAlex
01-04-2004, 12:12 PM
ok...so i checked the compression this morning and well, there isnt any heh heh. I'm almost 100% sure that its the piston rings. What leads me to believe this is the fact that the head gasket is in perfect shape and the valves are opening fine. Anyone else have any ideas?

MustangRoadRacer
01-05-2004, 08:37 AM
yeah, no oil will fry the rings.

-Josh-
01-21-2004, 06:12 PM
Piston rings have certain purposes:

Top ring- Seals comb pressure
2nd Ring- Seals Comb pressure, and scrapes excess oil
3rd Ring- Controls oil from entering comb chamer(to much oil, some is fine)

I highly doubt your car is not starting because of piston rings, it should still run if they are bad(not good, but should still run). There are many things you have to look at in a no start situation, first with(obviously) starting system components. Since you have a manual tranny it could be the throwout bearing not catching, the flywheel, starter motor...etc

But i would rule out piston rings, they may need to be replaced..yeah but they wouldn't cause a no start situation.

MustangRoadRacer
01-22-2004, 02:58 AM
well, If he is truly getting no compression, he won't be able to start the car.
If the car is getting no compression, it could be coming from the head/valves/gasket. all of which could eb damaged by the backfire.

89Turbo944
01-22-2004, 04:14 PM
Check you oil and see if it has any water in it. You may have cracked you block.

Also try, squirting some oil into each cylinder and do another compression check. Check toe valve in the compression guage, make sure it is not cloged, and stuck open.

The quage should spike everytime you turn the motor over, if not you are doing something wrong.

Volvord 784VC
01-22-2004, 05:12 PM
1st it would help to know what typr of car / engine you have but start with the basics!!
If the car was running and suddenly lost compression I would suspect timing belt (if so equipped). If the belt slipped as litle as 2 teeth you will not register any compression.

MustangRoadRacer
01-23-2004, 10:12 AM
how would timing effect compression?

Volvord 784VC
01-23-2004, 10:27 AM
how would timing effect compression?

On OHC engines the timing belt drives the camshaft, when the timing belt slips, the valves will not open/close in correct relationship to the pistons (ie. the intake valve may be opening on the compression stroke).

Timing belts should normally be changed every 60,000 miles to prevent slipping or breakage. This is very important on "interference" type engine that when the timing belt does slip or break the valves will contact the pistons causing extensive and expensive engine damage

89Turbo944
01-23-2004, 10:29 AM
Timing effects compression by:

Timing between the valves and pistons is crutial. If your timing is off the valves will open early or late and cause you problems. In this case they are most likley opening early. This means that the cylinder is not able to compress the air/feul mixture. Rather it is being pushed through an open valve.

89Turbo944
01-23-2004, 10:32 AM
I hate when that happens, you go to answer and 3 seconds after you hit post someone has already answered it. LOL

Volvord 784VC
01-23-2004, 10:47 AM
I hate when that happens, you go to answer and 3 seconds after you hit post someone has already answered it. LOL
:grinno:

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