green.Z

Hey guys, I wonder if any of you have run into this problem?

I am losing coolant at a rate of about 1 quart per 200 miles. There is absolutely no external leakage. I let the car run in my driveway for an hour looking for leaks.

I replaced the radiator cap, thinking that maybe it was boiling away. No help.

I've checked the oil for milky appearance, it looks fine.

I pulled all the spark plugs today expecting to find one colored orange Dex-Cool coolant colored. They all look fine.

The car still runs great. There is no smoke from the tailpipes.

The coolant is going somewhere. Could it be that I have a head gasket leak or head/block crack right beside the exhaust port? Can you guys help me from having to take it to a mechanic? Is there a good dye / UV light kit that you can buy to use at home to find these kind of leaks?

shoebox

Check the pipe that goes from the radiator to the remote reservoir. You will have to remove the battery.

moparman

I had a similar problem. Chased it for about a month. I could see no evidence of a leak, yet the coolant kept disappearing. I even pumped up the radiator with a tester. It would hold pressure. Replaced the cap. Didn't help. No coolant on the driveway. Even bought a sniffer that detects coolant in the exhaust. Negative results. No coolant in the oil. Where was it going? One hot day I went to the doctor. Came back out to see a large puddle of coolant on the passenger side of the car. Most of it around the tire. Got a flashlight out, popped the hood, and it was still leaking. It was a crack in the plastic tank on the right side of the radiator. Not the overflow. The theory I came up with is that the crack would not expand until the cooant was at normal hot temp for some time, and it would evaporate before hitting the ground as the crack was probably very small to begin with. I also thought that as the coolant cooled the crack would close. So check for leaks around the plastic radiator tank. You might also check to see all hose clamps are tight and no hoses are splitting.

raulz28

I had the same promble on a 94 z28 the outlet side of the tank had a crack on the bottom of the oil line at the top of tank. So when the radiator is full and when u drive away you would have missed it . Fill up the radiator when the car is off and then have a friend turn it on ,and keep watch for any leaks. to have it fixed sould be under 80 bucks.

green.Z

Found out the bad news on my coolant loss, verified by 2 mechanics. It's an internal leak, probably a head gasket.

Anyway, I think I will try to repair myself. The car has 212K miles on it. It still runs excellent and uses no oil.

Here are options as I see it:
1. Replace head gaskets only.
2. Replace head gaskets and get heads rebuilt.
3. Install a new long block.
4. Install a new short block and get heads rebuilt.
5. Get long block and heads rebuilt.
6. Dump in some Barrs Leaks Head Gasket Repair (the $10 stuff).

What do you guys think?

mrmint69

My water pump was going out. I could see green drops form but non ever hit the ground. I would loose a lot of coolant every month but could not figure out how it was so much. Once i replaced the pump it hasn't needed a drop since. 212k is only a matter of time. This is a great excuse to go for the most you can afford. If your married do it now while you have a reason.

1racerdude

Replace head gasket only on the side that is leaking and go on down the road. That is if the go fast bug hasn't bitten.

95Blackhawk

Dood,

How can we answer that question without info on your situation regarding money, time, willingness, etc.?

I personally took a $500 fix and turned it into a $5K rebuild but I had the money and its not my daily driver. It only had 70K on the clock but I know what I wanted eventually and went for it.

MentalCaseOne

Dude..

Check the Passeger Side Rear seat area carpet... Do you have any coolant smell inside the car? Do the air vents pump out unusually warm air into the car (a/c off)

Some weird smell into the passengers cabin?


That would lead to a Leaky Heater Core.

I let mine go for along time until one day I had to stop to fill up the radiator several times before I got home at night and next morning I fould a Pool of Coolant seating on the passenger side rear seat carpet area.


By the way Replacing the Heater core was way too easy..... First remove the three screws holing the Glove Compartment Door... gently rotate the Door and it comes out real easy .... then Las I recall only a few screws and the core comes loose.... Oh dont forget to undo the heater core hoses inside the engine pit.

Hardest part was finding the angle to pull it out.... once you find it remember to use the same angle to insert the new one in. Do your hoses back on and fill up with water to presure test it first. Flush the water out and new coolant goes in.... aproximatelly one hr if you are rushing or 2 hrs if you stop to count clowds in the sky.



Marvin

green.Z

It is now starting to leak coolant into the oil. Definitely a head gasket / cracked head or block issue. Thanks for the replies on this. I'm going to pull the heads this weekend, get them rebuilt, and put them back on with new head gaskets. Also thinking about doing headers at the same time.

01Z

How did the mechanics determine it was an internal leak?

Something to consider is Barr's stop leak, yes - even for a head gasket. However, since you are seeing it your motor oil,,, perhaps not.

I know many people will start with how it clogs the passages up and ruins the cooling system. If you do a search (google) you will find testimonials that deny the damage and tout the cure. The research and decision is yours. Personally, I would first do a compression check. I would then want to pull the heads, clean everything up and see about getting a valve job if the cylinder walls are good, your oil pressure is up and everything else you can check is sound. If you go this route I would think now to be a good time for some headers.

green.Z

Hey guys, got the car all back together. It runs better than ever. The head gasket was separated at the number 2 cylinder, and also a little at the number 8 cylinder. It was the metal ring part around the cylinder openings that failed. While I had the heads off, I got them re-done with a "competition" valve job. He put 2 angles on the valves and 3 on the valve seats. I ported the stock exhaust manifolds with a Dremel tool. Also, I replaced the O2 sensors, the spark plugs, and fuel filter. I cleaned the fuel injectors and throttle body while I had them off. I used the Felpro top end gasket kit, available from Autozone or Advance Auto Parts. Hope it holds up because I don't want to do this job again anytime soon!

Something very interesting: The cylinders still had the original cross hatching, that's with 212K miles! Yes, the rings may be worn a little, but still! I hope my religious oil changes are paying off.

It runs very strong, it is especially noticeable above about 3500 RPM. Maybe the valve job and exhaust porting was worth it. I can't wait to get to the track next spring!

For those of you thinking of replacing head gaskets: It is a BIG job. Allow at least 30 hours (the book says 20 hours, it took me almost 40 hours over the course of 3 weeks). You will pay a mechanic at least $1500 to do this if you decide to not do it yourself, make sure it is someone you really trust. It was very rewarding for me to do it myself, you will appreciate it more if you do it yourself. If you have a wife/girlfriend/family you may want to find a reputable mechanic. I spent a lot of time after work and on the weekends in the garage.

1racerdude

NovaTodd

That's a great outcome on the project. Enjoy it.