I just recently installed my motor after putting on a new timing belt, water pump, and clutch disc. Not that any of that has changed the situation at all but just a little info. It's a turbocharged 95 b18b. I've been losing coolant somewhere and I still can't figure out where its going. It was mysteriously disappearing even before I pulled the motor. Its not leaking anywhere and I had a pressure test where they pressurized the coolant system and found no leaks anywhere. I was thinking maybe the headgasket was leaking and coolant was finding its way into the combustion chamber, but the technicians assure me the system is sealed by the test they performed. I'm just looking for any ideas of where it might be going. I haven't even been boosting it at all because I'm a few things shy of going to get a tune on my hondata. After about a day of driving the reservoir is empty and I have to fill it up. No white smoke, no smell, no leaks. I'm stumped. Thanks.

 

I'd try to verify the head gasket again. I had that problem when I was less "Honda informed" and re-used the headbolts. The head worked loose of course and began taking coolant into the combustion chambers. yours could be blown in just one spot allowing the coolant to get out. One way to check by yourself would be to get the engine up to temperature, shut it off and remove each spark plug listening down the hole for any hissing sounds.

 

The head was never removed in the entire time I've had the motor in there. I doubt it was ever taken off. Were going to try another test here at the shop where they put some kind of turkey baster type thing in the radiator and youll be able to see the coolant change colors if there are exhaust vapors in there. The oil isn't milky at all either. I'm just hoping the head itself is not cracked because I doubt it will be able to hold the 270+ whp I'm planning to squeeze out of it. In fact, it probably wont hold that kind of boost even if there is a small leak in the headgasket. Oh well I'll see what happens.


Modified by highmilehatch at 8:11 AM 6/11/2003

 

I had the same prob, it turned out being a crack in the plastic top on my rad. It never leaked and I never saw puddles, I could even rage around on a hot day and jump out real quick and find nothing. It was holding press @ low rpm, it only leaked at high rpm and basically just evaporated on my headers. I fixed it w/ JB Weld and fiberglass neatly 2yrs ago. The crack was hard to see.
Just my experience...

 

what is the amount of the coolant that it is leaking? how much in a day?

 

check the seals that go on the pipe from the water pump to the thermo housing , I had this problem there are 2

 

look under the oil cap for any residue. Compression test also.

 

one way to find out if its going inside your engine is to pull the valve cover or the oil pan, if you see something that looks like mayonnaise then that's where its going. you shouldn't drive it if your not positive its not going in the engine, coolant is very abrasive and can ruin your motor if it mixes with your oil.

 

Update: We did a hydrocarbon test on the coolant and found no traces of a leaky headgasket. The tech assures me its not leaking from the head. Compression checks out ok. All the hoses are solid. One thing is, the car definitely runs hot, but does not over-heat. Another tech thought that because it runs so hot, it could be burning it up somewhere? But I don't see the correlation of the coolant loss because of how hot it runs. I put some special dye in the coolant and Im going to check for leaks again. I also plan on installing a pwr radiator to keep the temps down. So with the headgasket ruled out, does anyone have any other thoughts? Has anyone ever experienced a coolant loss because of how hot it gets?

 

Check your water pump. Maybe when you installed the water pump, you moved the seal out of place, or it could be defective.

 

It was losing coolant the same way even before the water pump. Hmm.

 

when i did my swap my engine had a warped head and i was loseing colent around the #1 cylinder and it was leaking behind the timming belt cover and was drying up behind there so i didnt figure out where my coolant was going till i took off the cover to check my timming belt. i had good compestion and no coolant was getting into my oil!

 

That's something I'll have to look into. If my head was warped it's possible that it is leaking externally and not actually making its way into the combustion chamber, but rather leaking out onto the block/head area. Once I check one last time for a leak with that dye, I'll be pulling the head and check for warpage. Thanks.

 

I had an old Bronco one time that was losing coolant, and I could not figure it out, no puddles, no coolant in the oil, and I poured in some Silver Seal, comes in a little container about the size of a pack of BB's for a BB Gun. Dumped it in the radiator, and it never leaked again. Just an idea.

 

Try pressurizing the cooling system while the engine is cold. Normally, the cooling system only leaks when hot (at which time the cooling system is under pressure). And if the leak is not really bad, the coolant evaporates before it gets very far (making the leak hard to find).

 

StorminMatt: I'll try that. However if I dont find anything I'm going to pull the head, check for warpage and go from there. I'll replace the headgasket and bolts and if it is still losing coolant, I think I'm going to boost it anyway. If it pops it pops. I know its not the best thing to do but at this point, I'll just keep adding coolant if I have to. Thanks for the help.

 

Before you pull the head, check the pressure cap on the radiator. When you talk of running hot, if you are venting superheated steam into the resevoir, it will evaporate the cold coolant in the reservoir.

An example. When I ran a 16 lb cap on my tahoe's I used no coolant, but I got to buy a 250 buck radiator every three years. I have run 7 lb caps for 20 years now, and I add a pint to a quart of coolant every month..... though not every day like you. But my resevoir holds 3 quarts........

Just another idea.