Cooling System Problems

The problems started almost immediately after I had the radiator in my car, a 1995 3100 V6 (~100k miles), replaced. They also replaced the thermostat. It was replaced because the plastic cracked/busted etc one day. This was shortly after I flushed and filled the coolant. Dunno if thats why it happend. But anyways...

My car has been losing coolant through the resevoir cap for about 2 months and I have been replacing it with water until I could get the problem looked at. I took it to a shop and they said I have an internal and external intake leak (as well as a broken strut torque mount and motor mount). All of which would cost me $1300 to fix. My question is would fixing this (I/E leak) answer the problem of the coolant pooring out of the resevoir cap.

Also, I took my car to another shop to have my brake pads replaced (under warranty) and I asked them a few questions. The guy said the problem could be much more simple than that. Talking with him pretty much agreed with what I thought was wrong after looking at the problem when I decided $1300 was too much money to put into this car. He says it could be a problem with the termostat along with a clogged hose casuing a problem with coolant return to the resevoir.

I was wondering if anyone could give me some feedback on what they think the problem could be. I don't think its an intake leak, especially internal, because I have probably added about 2-3 gallons of water into my coolant resevoir over the past 2 months to replace the loss of coolant. The only time I have had a problem with overheating is one morning a few days after my LOW COOLANT light came on. The problem was fixed by letting the car set for about 2 minutes and filling it with water. When it overheated the needle on the termostat was all over the place but once I replaced the water it stayed at its normal opperating temperature, which is about 1/8th in. past the second notch (between 100 and 220).

Also, assuming the problem is an internal and external leak, is it possible to repair that myself along with checking the hoses for a clog and replacing the thermostat (just to be safe) and not spend so much money. I would love to spend no more than $200 to fix this (they estimated around $850 to fix just the leak).

The first thing you need to do is to attempt to locate the leak. This sounds like you may have a heater core problem that is causing the water to leak out of the drain rather than into the car. If you put cardboard under the car and start it and allow it to heat up you possibly will find where the leak is. That much water has to go somewhere!

Also check the oil to make sure there is no water in it. If not then the only other place this water can go internally is to go out the exhaust. If you are not seeing a plume of smoke out the exhaust then that is not an issue. This would indicate an head gasket problem.

Finally, check the area around the water pump. Sometimes these will leak and not show up anywhere. Just a thought.

also to add to what GTP DAd said, look under the throtle body(right side), on top of the engine block, the 3.1's lik to leak out the intake and the coolant pools up down there. Its hot there so the coolant/water evaporates quick.
Just my :2cents:

Two mornings in a row I checked the oil dipstick for air bubbles after they told me that it was an internal leak, I figured it was a leak into the oil, didn't know exahust leak was possible. However, I didnt find anything either time. Both times I let the car sit over night and checked in the morning.

As far as the smoke, it's hard for me to tell because of the cold weather and also because it happens infrequently. But, there is, what seems to me, a bit more smoke comming from my car than I see in other cars around me when I drive. I don't know if that is indicitive of a problem though. The only thing about that is the problem started long before winter and I never noticed the smoke then, only in the cold weather months.

As far as I can tell though the only place coolant is comming from is the resevoir. However, I will try tomorrow to check for a leak under the throttle body as well as try to get some card board to stick under the car.

Hopefully Ill have more to post tomorrow. Thanks a lot folks :).

i dont think you'll find "air bubbles" in the oil, look for chocolate colourd stuff or whitish foamy. It'll be on the oil fill cap too, along with the dipstick.

If it is just your overflow spilling over you might try a new rad cap.

i dont think you'll find "air bubbles" in the oil, look for chocolate colourd stuff or whitish foamy. It'll be on the oil fill cap too, along with the dipstick.

If it is just your overflow spilling over you might try a new rad cap.
When I did my checking I don't remember seeing anything but the oil. I'll try to check again in the morning but more than likely itll be this weekend. Just too damn busy during the week :(. I drove my car a lot (60+ miles round trip) on the highway and I didn't have any problems so hopefully it can hang on till I get it fixed.

Well, I was planning on doing that along with any other stuff I was going to do. However, thinking about it...it makes more sense to try that first before doing anything else. It will also work out better for me overall. I can try the new cap for a week and then if that isn't working I can try something else.

As far as the smoke I still didn't really notice anything that would seem excessive *to me*. With that being the key phrase, I am still not sure what to look for as far as smoke. But it seems to me to just be the normal smoke you get out of an exaust during the winter days.

If your intake gasket is bad your oil will look milky, kinda grayish, if it looks brown like normal and your going thru that much coolant i'd say its not your intake. You mentioned you replaced the thermostat the same time as the radiator, then your problems started, did you do this yourself or have a shop do it? Either way it sounds like they used a cheap thermostat and it sometimes sticks, causing the overheating, making the fluid boil out of your over flow coolant bottle. Your coolant bottle cap should let fluid and air escape it, so I don't see where getting a new one will help you.

Here's my 2 cents, cheap thermostats are nothing but a waste of money, i've seen too many stick, buy an OEM thermostat, yes that means go to a dealership and get one, if you've ever compared the two there is a very big difference, if your in a pinch go to a Napa Store and get the best one they have. From the info you've given im putting my 2 cents on the thermostat.

The other option is its a head gasket as GTPDAD stated, this could be checked with a simple compression test. If you have low compression in one cylinder then theres a good chance you have a bad head gasket, if they are all equal then the gaskets are probably fine.

the compression test for the head, it works yes, but, recently My headgasket was blown and the coolant jacket leaked into the oil drain. So my oil was lookin like a milkshake.
But all the compression tests read fine, 100+psi checked it 4-5 times on every cylinder. the only way I found it was by taring it down and actually investigating it. Just my :2cents: