Coolant Loss

Hi Dear All,
My windstar 2000 lost 500 ml (half quart) in 9 months about 6000 km. I do not see any leakage or coolant in the exhaust. No mixing of oil in the resevoir. I could not appriciate any coolant in the engine oil. Engine oil is normal. No change in level. Is it normal?

Just my opinion, I don't think it's a big deal. I'm not aware of common issues as far as coolant loss for this vehicle.

Others here may have a different thought.

Which engine, 3.8 or 3.0??

Have you checked the water pump seep hole??

There may be a rather innocent leakage somewhere ... but it could possibly be trouble. For the price of one oil sample ($35..??) checked by Blackstone Labs ... the question will be answered and you will be able to sleep well ... or, make repair/sales plans.

.... and then sleep well. Its all about the quality of sleep!

Thanks for all,
It is 3.8, dear Tempfixit, where is the seep hole is located?

The 3.8 does have troublesome internal leak potentials : the lower air intake gasket and seal set, and the front engine cover gasket and coolant pump-port seals. Both of these seal sets, if leaky, will pass coolant into the crankcase.

The coolant pump shaft has a hot liquid seal ... ceramic against polished metal. There a weep hole, though the housing ... usually on the bottom of the shaft, that lets coolant that leaks/passes the seal ....flow to the outside world. This is to protect the bearing cartridge from coolant.

Don't forget the infamous "ByPass Pipe" and "Y Pipe" culprits. Also check the Degass Bottle Cap for a cracked seal that could be letting coolant steam out of the system. And also the heater lines going to the rear A/C unit thru the undercarriage

I would run the engine at normal temp for like 20 mins or so, place a clean cardboard under to cover the whole engine bay area (including the firewall) and try to smell for coolant, If you can smell it the leak is big enough to cause big trouble and also checking the cardboard underneath for new coolant drippings which may need to be left overnight to catch!

I would check the gas cap. The "clicking" type caps are, in one word, CRAP. There are videos on youtube about it and these hold around 4 PSI, the system is designed to run at 16PSI. If the pressure drops, the coolant can start to boil and that might be the source of your coolant loss.

If you still have one of those, replcae it with any $5 replacement from the store. The newer desing has a bigger underside centerpiece and DOES NOT clicks.

Oscar.

Found the leak It was the plastic on the sides of the radiator....repaired. After few weeks again loosing now leaking behind the engine This time the Plastic T behind the engine. cut the pipes and replaced with the ordinary plumbing T. The T shaped pipe from Ford too much expensive. After a few weeks another leak this time very difficult to find the source though leak was very much obvious the I replaced the heater core. in 2015. Today I see water coming from the silencer may be now head gaskit http://staticaf.com/vbulletin/images/smilies/evil_lol.gif

Although coolant loss can be caused by a faulty head gasket, even without the tell telltale overheating and displacement of coolant, my experience has been failure of the the lower intake manifold seal. This can easily result in intake vacuum sucking coolant through the seal since there is ~45 psi difference across the elastomeric gasket. The seal often fails due to the thermally induced movement of the aluminium heads and intake manifold on the steel engine block. You can usually see it with the manifold removed because there will be corrosion patterns on the head and/or manifold where the seals make contact.

Unfortunately I didn't have much success with just a simple remove/replace of the gasket, I believe due to the corrosion at the sealing points, which prevented a good seal.

Check for bubbles in the coolant, or a rapid increase in coolant pressure on the cold engine before heating can be held responsible for the system pressure. Those are signs it is the head gasket.

This webpage may be helpful to determining if it is a intake manifold leak or a head gasket issue.

https://www.stangnet.com/mustang-forums/threads/blown-head-gasket-vs-bad-intake-gasket-how-to-diagnose-coolant-in-oil.632038/

Also, check the plugs for signs of coolant (exceptionally clean, for example).

To repair, I found that I had to improve the quality of the surface to be sealed. I read that one of the identified causes of leaky intake manifold gaskets in V-6 engines is due to the thermal expansion induced movement of the gasket across the head face. When the machined face is too rough, the gasket material is damaged and leaking begins, getting worse over time as the gasket is further degraded.

I improved the surface finish by filling the corrosion pits with JB weld, then polishing the mating faces of the intake manifold and cylinder heads with ~1000 grit abrasive paper. I did this while the engine was disassembled for a rebuild, but I believe it could be done with the heads mounted to the block, but you'll need to be careful to control the debris from the polishing process.

I did this about 70,000 miles (5 years) ago, and I'm now starting to see coolant loss again, but this has worked better than replacing the gasket alone.

As mentioned, you can contact Blackstone Labs for a sample kit that you can send a sample of your engine oil in for analysis. This is the only way to know if you are getting coolant into the engine oil.

Water out of silencer.. if this is the rear part of your exhaust system, it is NORMAL for water to come out there. Particularly when the engine is cold. My '96 had a small hole in the bottom of the rear most muffler (silencer) specifically for this reason, to let the water drain out.

Also, as mentioned above, the head gaskets are most likely just fine.
The lower intake manifold gaskets are known to leak, and can cause some of the same symptoms of a head gasket leak.....coolant into the cylinders due to being drawn in through the intake....as well as coolant into the oil.
The new lower intake manifold gaskets are improved from the original, so the problem of the originals has been fixed.
When replacing the lower intake manifold gaskets, they are to be DRY FITTED, meaning no sealants on the gaskets surfaces. On my '96 3.8L the instructions were to apply a small dapp of sensor safe sealant at each end of the end seals, where they meet the lower intake manifold gaskets.

Also, the instructions say to NOT use metal tooling to clean the surfaces in preparation for installing the gaskets. This is because metal tooling can cause small scratches in the metal surfaces, which leads to leaks.
Sensor safe sealant at the ends is because general purpose silicone sealant releases chemicals over time that can damage oxygen sensors.

The front cover gasket was also mentioned. This is also called timing cover....same thing.
This is the plate that the water pump is mounted to.
The new gaskets are improved so, as with the lower intake manifold gaskets, you should only need to do this one time.
However, the front cover / timing cover gasket job is a REAL pain to do due to the location.

Also mentioned above is the cross over pipe.
THIS is different on 1999 through 2003 than the one shown in my pictures for 1996.
Mine passed through the lower intake manifold and looks different from yours.
Yours passes between the upper and lower intake manifolds....so it is on top of your lower intake manifold.
THIS video shows your cross over pipe at around the 9 minute mark.

https://www.youtube.com/watch?v=AWomi-tfjoc

If you remove the upper intake manifold, inspect and clean the EGR ports in the lower intake manifold while you are right there.

Thanks Wisiwind!
Ultimately, till today, I have changed all the coolant system radiator pipes heater core and both fans, one by one except the rear heater core. One fixing resulted other leak. Now almost every 3 month I have to put a quart. It is acceptable

Haven't read the whole thread, but if you haven't replaced it go ahead and get a new radiator cap. If they don't seal properly they can actually let coolant evaporate. You'd never notice a leak, because its not really leaking.

Thanks replaced bottle and cap also. May be my country is hot normal temperature remains + 40 C :lol2::lol2::lol2::lol2:

Found the ultimate culprit it started causing intermittent code P0301 with no driveability issue. see also https://www.automotiveforums.com/vbulletin/showthread.php?t=1158769it. It was slow leak in to the head no 1 causing intermittent