Engine/Transmission (1998.5 - 2002) help: coolant dissapears

[cmills]

Here's the deal, whenever I fill my coolant overflow bottle to the full mark it always goes back down to around the add mark and then it just stays there, it has done this for as long as I can remember, well I just had the engine rebuilt with a new block and a new head also and it is still doing the same thing. Any Ideas??

 

[JohnE]

Really stupid question.

Have you checked the entire coolant recovery system? The bottle may have a hole, the line to radiator neck may be bad, and/or the radiator cap may be bad.

 

[cmills]

I can't see where anything is leaking: the bottle, any hoses or anything else the water pump weep hole is dry and like I said the whole engine has just been rebuilt less than a week ago. I'm clueless

 

[ToolManTimTaylor]

Have you checked for coolant in the oil? Does the exhaust produce whiteish smoke and smell sweet? Air can work its way out after a while however to keep loosing it ... . odd especially after a rebuild. It is not impossible to have a bad head gasket ... or one that isn't sealing properly.

 

[cmills]

I used to do oil analysis before I had it rebuilt and never had any signs of coolant in the oil. I just don't know whats going on with it

 

[ToolManTimTaylor]

Right and was it using coolant BEFORE the rebuild?

 

[cmills]

yes it was doing the exact same thing before the rebuild

 

[ToolManTimTaylor]

Hmmmm Well now I am Isa stumped Nomatter how much ya put in eh? And it Allways goes down to that level. Cold Nor Hot. Hey wait a sec ... ... How's the heater core?? Carpet wet ... or better yet is the condensate drain showing residule coolant residue or does the windshield fog up in the A. M????

 

[cmills]

what the heck is a condensate drain and where is it? I have't noticed the carpet being wet but then I don't sit on that side either. I don't guess I 've used the heater since I got it rebuilt but I don't guess that would matter because the coolant is flowing through there all the time anyway, right But why would it always drop to the same level and stay there? by the way thanks for the all the responses so far.

 

[ToolManTimTaylor]

Well the heater core may have a pinhole leak that is leaking causing the level to drop. It probably is such a minute leak that it mostly could be leaking out the drain (Condensate drain ... . A rubber open ended tube located under the truck up on the firewall / floorpan area just behind the turbo) On occasion maybee the leak is enough where the carpet may become wet. This scenareo most likely will be accompanied by a strong antifreeze smell when the vent is first turned on in the HEAT position.

 

[JohnE]

The before and after comments is why I thought the coolant bottle has a leak.

A fresh refill of coolant always takes a few weeks to completely purge the air. Mine took longer as the head gasket was done in April and we haven't had enough summer to really heat the engine until into August. Finally had to top off the coolant bottle.



BTW, why the complete engine build?

 

[cmills]

I just went down and checked and the carpet was dry. If it was leaking why would it only leak down to that level and stay there?

 

[ToolManTimTaylor]

Ahhh yes thank you both for pointing that out! LOL I somehow did not see The "to around the add mark and then it just stays there" Part. I was seeing a leak LOL!



I would also venture to bet that that resevoir tank has a leak as well. Right at the add mark level. It may be such a leak that may leak as you drive kinda thing and not when you pour it in deal.

 

[cmills]

I'm going to add a little to it in the morning to just bring it up a few inches and I'll check the radiator and make sure it is full and I'll even run the heater for a while. I'll be pulling a trailer some tomorrow, so it will get nice and warm. After I drive it a little I'll look and see if it is leaking somewhere on the bottle. I would think I would be able to tell if it is because it leaks probably a quart in a few days then it stops when it gets down to the add mark. Thanks again for the help, I'll write back tomorrow and tell you what I find out.

 

[jrobinson2]

Mine's done that since it was new, it seemed to slow down for a while but its still there, it goes down a little below the add mark a couble times a year and seems to stay there if I don't re-fill it. My truck and I decided since there was nothing in the oil samples and nothing on the ground we would call a truce, I dont mess with it, it dont mess with me, seems to have worked fine for about 120,000 miles so far

Jared

 

[MPalachuk]

When I worked at a fleet, The Peterbilt trucks would loose coolant till you could just touch it in the top tank. We would fill it up and next time in it would be down to where you could just touch it, So we quite putting coolant in and it would stay where you could just touch it. So we just left it alone and everyone was happy, the truck and us. So let it go down and watch it if it stays just let it go and keep an eye on it.

Good luck

 

[cmills]

you're right I should probably not worry about it unless it keeps getting lower but I just wonder what is going on. I went out this morning and added some coolant to it enough to bring it up a few inches and then I drove it quite a bit I looked at it a couple of times and could not find any leaks on the bottle. I will check it tomorrow morning when it is totally cooled down and compare it to where I filled it this morning (I was smart enough to mark the level)



BTW, It was rebuilt because the rings were stuck on the number 6 cylinder from way too much idle time and worn valve guides letting oil get in the cylinder, so I went ahead and had them do the whole thing while they had it out since it had 192,000 miles on it.

 

[tp0d]

Hmm... one possibility.



If you add coolant when the engine is cool, and all the fluid is cool, the coolant takes up less volume due to expansion. When you heat all those gallons, you expand at a rate of 3% of capacity per 80 degrees. When the engine is hot it could be pushing everything you added back out of the overflow, then when it cools it would drop back to the lower 'add' level. Have you checked the truck when its hot to see if its full to overflowing? just a possible point from a plumbers point of view



good luck



-jerry

 

[cmills]

Yeah, I have checked it hot and its not even close to the top

 

[Oil Burner]

this is in left field but I had the same symptoms. Always added coolant and ended up around the low mark. turns out my tstat gasket was bad. it was bad from the factory. i always had a slight leak. i even replaced the tstat housing, so i have a spare if anyone needs one



Anyway, the 50 cent gasket cured all problems (from napa). once those things are compressed, they are finished. I bet they had mine on and off once during the build.



just a thought. for a buck it is worth a try. Oh yeah, it was hard to see the leak because the coolant would leak out very slightly and burn off on the head. I only noticed it when I changed the t stat and reused the gasket and then it was really bad.



-Jason