Hi all, Luckily its not my Buick but my daily driver. Its a '95 Tacoma 3.4l. My coolant is gone every month or so, with no leakage anywhere. I have about 20,000 miles on the rebuild and 300k on the car. I recently replaced the thermostat, yet I think that was just a waste of time and money. Could this be caused my a faulty radiator cap? Any ideas would be greatly appreciated. Best regards, Mike
What does your oil look like? It can't just cease to exist, so it's going one of 3 places: on the ground, out the tailpipe, or into the crankcase.
If the oil is clean and there is no obvious white smoke out the tail pipe after it's warmed up, buy/borrow a radiator pressure tester. Pressure to cap pressure and look for pinhole leaks. Same tester should also be able to check the cap.
Mike, Pressure testing is the correct route to go to really pinpoint the problem. Do you detect an odor of burning coolant once you park it? Just went thru this recently as over a course of time, my wife's Honda Odyssey (pretty sure satan was a previous owner) lost all its coolant. Pressure test found that it was both rear lines to the A/C had rusted thru....coolant was slowly seeping out and burning off. No smoke to be seen.
I have a similar issue with my Suburban. I never thought to check the lines for the rear heating. It did have a bad radiator and leaking water pump that were replaced last year.
Thanks all for the ideas. I'll check though the list. Interesting enough....I recall talking to a mechanic says they have a galvanic corrosion issue as only one head is grounded, so I'll need to add the ground to the second head. Happy Sunday All, Mike
My old 3.8 Buick used to lose a lot of coolant, it went though the intake and was burned. The only thing that I noticed was slightly worse fuel mileage. There was a hint of an antifreeze or a sweet smell out the tailpipe, but no evidence and no leaks.
Were those motors part of the notorious GM intake manifold issue? Maybe look at the plugs and if one is "extra clean" then worth checking intake gaskets. -Bob C.
I had that issue on my BBC Camaro. I chased that issue for 2 years. I finally found the issue when my alternator died. Had it not been for it dying I would not have found it. But I also suspect the radiator was the reason it died. I would lose about 1-2 inches of fluid in my radiator each drive. But not in the oil and absolutely no leaks I could find. No drips on the ground etc. So turns out, when it got up to pressure there was a pinhole leak at top of radiator. Enough for it to "spray" a fine mist of radiator fluid. Which just happened to spray right onto the "fan" of the alternator, which I turn dissipated this fine mist basically to the atmosphere. How I found it was there was a fine green (coolant) dust inside the alternator. pulled the rad, I ended up replacing it with a new one, as I suspected it may have suffered and electrolysis issue. I now have a sacrificial anode
