My car is losing coolant at an alarming rate. About a gallon every two months or so. Yet I can't seem to find where it's leaking coolant. I don't see puddles under the car, I don't see it dripping coolant anywhere. Everything near the waterpump is dry.
Dark. Not milky at all. I did have to add quite a bit of oil too but I'm not sure those two are related since it has been quite a while since I had last checked the oil.
I did replace the water pump last summer. But AFAICT, there are no leaks there.
The reason I replaced the water pump was because I had the same problem with having to keep adding coolant, and I probably ran the water pump dry at one point causing it to fail. So this isn't a new problem, it's one I've been having for quite some time now.
Oil and water disappearing, still sounds like a head gasket to me. Is the exhaust clear? With such a slow rate of leakage, it may not be showing up yet...
Leaking w/ engine hot w/o wet on "floor" = system reach ~ 15psi and then leaking...
Hoses etc often leak under pressure and little to nothing when "cold." use rad tester to pressurize when cold can help here but not always. Plus most testers won't fit Fiero w/o taking hood off.
Internal leaks doesn't always show in oil in sump/pan. Try this... Pull spark plugs and keep them in order. Look at plugs. Does some plugs look cleaner then others? True then coolant is leaking to clean plug cylinders.
Examples: Can be iffy intake man or casket because intake has coolant flowing to some intake runners. Common problem for L4 w/ #4 cyl and coolant port but V6 V8 and others can have same. When this happens, coolant often "burns" and never get to oil pan + "burning" coolant can kill the cat and O2 sensor.
Head gaskets can leak coolant into cyl but often leak exhaust to coolant system. When this happens, try putting Exhaust tester probe next to coolant in T-stat house or rad neck w/ cap off. Do Not dip the problem into the coolant. Exhaust gas there you hope just a "blown" head gasket. Often this causes "fake" boil over like overheat but coolant is still too cold to boil even w/o system pressure.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
How many miles (or kilometers!) over that 2 month span?
------------------ 1965 Tempest 400 CID 2018 Chevy Colorado Z71 3.6 2017 BMW X3 3.0 T 2015 BMW 535iX M Sport 2008 G6 GT "Street" Coupe 2005 Buick 3.6 Rendezvous
I was just thinking to myself the other day that Cliff P never seems to post about his car...
How is your passenger floorboard? Is it damp? Crusty? how often is someone on that side? Slow heater core leak could go undetected.
Coolant reservoir, does it hold liquid? Is the tube ok? Driving and with the temperature rising coolant expands and goes to the reservoir. Its then supposed to go back after but if some was lost in translation on the road that could go undetected
These are long shots/oddballs ive had in the past. I lean more to head gasket myself by default.
[This message has been edited by skywurz (edited 03-07-2021).]
That was my thought. If the seal is bad (or compromised by dirt or grit) it can allow coolant to drain out through the overflow tank, and allow air to be sucked in. I had the same problem with my car. The "grit" was leftover Cooling System tabs that someone recommended for my 4.9. The grit stopped the cap from sealing properly.
Cliff, I think you should do a compression test first off......See if there are any low cylinders which may point more strongly to a head gasket issue.
If you've eliminated the possibility of a leaking heater coil, radiator, water pump and radiator hoses and pipes, try pulling your spark plugs and checking them. If the insulators around the center electrode any are very, very clean you may have a head gasket leak, especially if you are seeing a lot of water vapor in the exhaust.
I suggest an oil analysis. It will tell you many interesting things; with one being if you have antifreeze in your oil. Even if you don't have antifreeze in your oil, you could have a bad head gasket. At this point you could try one of the many head gasket elixirs you add to your antifreeze. If this fixes your problem you can run it as is, or dive in and replace your head gaskets.
------------------ Stanton '88 Formula, red on gray
That was my thought. If the seal is bad (or compromised by dirt or grit) it can allow coolant to drain out through the overflow tank, and allow air to be sucked in. I had the same problem with my car. The "grit" was leftover Cooling System tabs that someone recommended for my 4.9. The grit stopped the cap from sealing properly.
That was my thinking, also the spring on the cap could be worn and not holding the system back to proper pressure level before allowing coolant into the expansion tank.
With the amount of coolant being lost there would be clear signs of a leak in the radiator, hoses, pipes if they had issues along with puddles under the bad area. If the heater core was leaking that much inside the car there would be a wet floor and smell of antifreeze. If that much was leaking into the engine, it would either be smoking like crazy with a sweet smell coming out the exhaust or the engine oil would be overfilled and milky.
[This message has been edited by TM_Fiero (edited 03-08-2021).]
If coolant is leaking from the radiator cap seal evidence in that leak would show after a drive when you are parked. If the cap is bad you may see coolant on the ground or the overflow to the bottle would increase excessively. I would just invest in a new 16 lb cap and also do a pressure test of the cooling system. The pressure tester is a special tool but not terribly expensive.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Cliff, 1) Is your car an automatic? How old is the radiator? Is the radiator the original?
I'm guessing that it might be the radiator inlet tank. They first only leak when the car is hot. And if the car has cooled down by the time you get home, there would be no evidence of leakage. So you could have a perfectly clean parking spot.
Eventually the tank will leak more and more so that it is leaking even within a few minutes of operating.
Cliff, 1) Is your car an automatic? How old is the radiator? Is the radiator the original?
I'm guessing that it might be the radiator inlet tank. They first only leak when the car is hot. And if the car has cooled down by the time you get home, there would be no evidence of leakage. So you could have a perfectly clean parking spot.
Eventually the tank will leak more and more so that it is leaking even within a few minutes of operating.
Now that I think about it, this is a very good possibility. My 86 2.8 did this and it was a manual. No evidence of leakage on the floor. What finally tipped me off was a brief puff of steam I saw up front when parking after a drive. Replaced the radiator, problem solved.
------------------ 1965 Tempest 400 CID 2018 Chevy Colorado Z71 3.6 2017 BMW X3 3.0 T 2015 BMW 535iX M Sport 2008 G6 GT "Street" Coupe 2005 Buick 3.6 Rendezvous
