Losing coolant

I'm having to add about a gallon of coolant every few weeks, maybe three. Can't see where it is leaking anywhere and the oil analysis did not show up any in the oil.
Does this mean it is burning out the exhaust? Haven't seen any smoke or smelled anything unusual. I only have 371,000 miles and it still runs good. I can tell when it's getting low because the temp gauge will go up when I slow down or stop. What gives?

only have 371k, :lol:

Didn't you just do an LIM/UIM job Wally?

If so, I hope you don't have a head gasket issue with your mileage.

I'm having the same issue. I already did the UIM/LIM gasket about 10K miles ago. Worked for a while, but now I'm losing more coolant than ever, but none in the oil. Can't find the leak anywhere by inspection, all the hoses are good. I took it to a shop to have it diagnosed, but when they pressurized the system they just blew out the seal on the that coolant 90 deg. elbow on top of the water pump. What else can be leaking? Water pump gasket? Front cover gasket?

pull the plugs Wally and check for discoloration.

Also check your water pump/bypass elbow area.

pull the plugs Wally and check for discoloration.

Also check your water pump/bypass elbow area.


You mean pull the front three plugs, don't you. I'd rather be kicked in the gonads than deal with those back three plugs again.

only have 371k, :lol:

Didn't you just do an LIM/UIM job Wally?

If so, I hope you don't have a head gasket issue with your mileage.

I think it was 3 years ago when I did the LIM/UIM job, somewhere just over 300,000 miles. I can't find any dripping but I am finding some greasy, oily looking spots about 10 inches in diameter, on the driveway. And the front side of the oil filter has that same residue on it.
The water temp only seems to go up when it gets low on coolant. Sure hope it's not a head gasket. I suppose that would give me a chance to practice my mechanical skills when I retire in 2 weeks.

The back 3 arent so bad. I'll come over and yank them out for you. Just get one of those swivel spark plug sockets for the one blocked by the O2 sensor. You'll be fine.

I have a feeling that if your car was consuming coolant through the head gasket, that you would also have combustion gasses entering the radiator. Fill it and leave the cap off and check for bubbles at idle and blip the throttle. Maybe your UIM has warped (didnt your replace it ones already?)

After I did my LIM gaskets, mine lost coolant out the temp sensor and the t-stat o-ring. The temp sensor appeared dry and I kept on replacing the t-stat gasket because I thought it was dripping from there. It would lose about half the radiator in a few days. Then I finally rented a coolant pressure tester and pumped it up. The rest is history.

BTW, congrats on retirement.

The back 3 arent so bad. I'll come over and yank them out for you. Just get one of those swivel spark plug sockets for the one blocked by the O2 sensor. You'll be fine.

I have a feeling that if your car was consuming coolant through the head gasket, that you would also have combustion gasses entering the radiator. Fill it and leave the cap off and check for bubbles at idle and blip the throttle. Maybe your UIM has warped (didnt your replace it ones already?)

After I did my LIM gaskets, mine lost coolant out the temp sensor and the t-stat o-ring. The temp sensor appeared dry and I kept on replacing the t-stat gasket because I thought it was dripping from there. It would lose about half the radiator in a few days. Then I finally rented a coolant pressure tester and pumped it up. The rest is history.

BTW, congrats on retirement.

Already got the swivel socket for the plugs, so come on over. I have replace the upper intake manifold. Just threw the old one away last month and it was not in bad shape.

Get a combustion leak detector test done on the cooling system to confirm head gasket issue. Some retailers sell the test kits, otherwise find a radiator shop to test.

Do you see any horse residue anywhere Wally? some may be blocking airflow through the radiator, :lol:

Wally, I just ordered my plane ticked to georgia. One Way, I figure I will just move down there so I dont have to deal with the salt in the winter here. See you in about 2 weeks!

Wally, I just ordered my plane ticked to georgia. One Way, I figure I will just move down there so I dont have to deal with the salt in the winter here. See you in about 2 weeks!

So you'll be here in time to go to the night race in Atlanta on Labor Day weekend? I'll save you a ticket.

You know it! Thanks! (I wish)

Tim, you should be in bed asleep.

Your right.

I just had to check my email quick, waiting on a reply about a new job....

Any word on the coolant leak?

Your right.

I just had to check my email quick, waiting on a reply about a new job....

Any word on the coolant leak?

Added another gallon over the weekend. I think I must have a tiny leak somewhere. I keep thinking it will get bad enough to find, but so far I can't find it. I did notice that the front of my new "orange turd", as doctorhardware calls it, is black. So it appears it may be getting worse and washing oil and grease down toward the filter.

Wally, have you checked the heater hose connections and the elbow at the belt tensioner, as well as the o-ring on the bottom of the tensioner where it goes into the timing cover? Your 97 only has one plastic elbow at the top, but has an o-ring at the bottom (where the later models have another plastic elbow).

Wally, have you checked the heater hose connections and the elbow at the belt tensioner, as well as the o-ring on the bottom of the tensioner where it goes into the timing cover? Your 97 only has one plastic elbow at the top, but has an o-ring at the bottom (where the later models have another plastic elbow).

I have not checked that area specifically yet Rich, but will check it out. It's not a dripping leak that leaves a puddle, so it will be kinda hard to find until it gets worse, especially with the condensation off the air conditioner.

when those o-rings and hose fittings start to leak, they are mostly just seepage under pressure. You may not even be able to get it to leak in the driveway, they tend to leak only at speed/higher rpm when the car is warmed up.

Wally, go and rent a coolant pressure tester from o'reilley's. Its free to rent and you can keep it as long as you need it. Pump the system up to 16psi and I'm sure you'll be able to find the leak.

when those o-rings and hose fittings start to leak, they are mostly just seepage under pressure. You may not even be able to get it to leak in the driveway, they tend to leak only at speed/higher rpm when the car is warmed up.

yeah, when mine went bad on the 98...i didnt have any coolant on the ground either. i was putting in a gallon every 2-3 days.

i thought for sure it was the LIM, but i pressure tested the system, and as soon as i did that...i could hear noises on the passenger side. sure enough look under the tentioner and there was coolant leaking out.

Wally, go and rent a coolant pressure tester from o'reilley's. Its free to rent and you can keep it as long as you need it. Pump the system up to 16psi and I'm sure you'll be able to find the leak.

Got a tester and found my leak, defective gasket on the water pump. Sure enough, with no pressure it does not drip. It was around the bottom bolt on the pump and I had to use a mirror and light to see it.
Thanks you guys.

I replaced the water pump and see no leaks but it still won't hold pressure. I don't think that is normal.

uh oh, multiple leaks.....

Where else is it going? Does it leak down immediatly?

uh oh, multiple leaks.....

Where else is it going? Does it leak down immediatly?

Yes, it leaks down immediately......about 15 seconds from 16 lbs. to about 4. But I don't see any signs of water anywhere. A leak in the tester perhaps?

Yes, it leaks down immediately......about 15 seconds from 16 lbs. to about 4. But I don't see any signs of water anywhere. A leak in the tester perhaps?It appears that my leak is fixed. After filling the system and purging the air then a 100 mile round trip to work, the coolant level was still full after the car sat for about 4 hours. I repressurized the system and this time it only took about 2 pumps to reach 16 pounds. It will still leak down slowly but there is no coolant dripping this time. I think the tester has some leakage.

Sounds good! Nice work! Good for another 100,000 miles.

Sounds good! Nice work! Good for another 100,000 miles.


Since I only have 5, count'em 5, working days left, that's not likely. But then who knows. Stranger things have happened.

You and the Grand Prix are going to retire at the same time?

I know its a good time to buy a car (especially from Government Motors). You can pick up a 2008 GXP with 20,000 miles in my area for $16,000.

If you had access to a bore-scope tool you could potentially pull spark plugs and inspect the piston tops.

If you are ingesting thru the intake tract you'd most likely see one or more pistons shiny new (washed) instead of the typical carbon-black.

I would think a blown head gasket would manifest itself in boiling coolant of some magnitude which likely has to go out the radiator cap and/or the overflow bottle.

Another thought is to do a compression test...could possibly show the weak cylinder or help make decisions about your piston ring packs and the cylinder bores' condition.

Wally, I just ordered my plane ticked to georgia. One Way, I figure I will just move down there so I dont have to deal with the salt in the winter here. See you in about 2 weeks!We would be happy to have you down here Tim, however, things in Atlanta are not like like they use to be, or in the small towns in Minnesota, we have smog, a high crime rate, terrible traffic congestion, inflated home prices (considering the market) and taxed to the max. Good luck on your endeavor and let me know what you decide. BTW, read the paper every day while here, you will be amazed at the crime statistics. If you need any advice as what part of Atlanta to live, let me know. Good Luck! :rolleyes:

Unfortunately it is the sign of the times. I remember when you could leave the door unlocked and open. If you would do that now there would be nothing left.

I could start with my political views, but Bob put a stop to that once already and I don't need any more demerit points, so I better keep my opinions to myself.

If you need any advice as what part of Atlanta to live, let me know. Good Luck! :rolleyes:

I used to live in Marietta, GA which is in Cobb County. Northern suburbs. If I ever moved back there it would be Kennesaw. Atlanta itself was destroyed by the liberals a long time ago but I am not expressing any political views about it. :uhoh:..........:rofl:

Neither was I, just stating the facts. How unfortunate that they are. But one thing it is truly sad.