Ranmatchi

Hey all, first post here and hope you gurus can help point me in the right direction on my 3rd gen 'teg.

I've got a 94 auto LS with 160K on the clock. Just replaced the radiator the other day (damn plastic one cracked) with a metal single core radiator. It was smaller than what I had in there before (3 core), but it was cheap and the only one I could get on a days notice.

Every once and a while, the temp still creeps up when the car is at a stop. Once I get going, it's fine again. I was thinking fans, but I've had both of them come on while the car is at a stop. The coolant overflow bottle cap is loose and doesn't seal well, but it doesn't leak at all. Could it be an intermittent problem with the fans, the coolant bottle cap not sealing all the way, a stuck thermostat, or just a sucky radiator?

Also, I cleaned up under the hood with some degreaser, and now the car's acceleration is really sluggish, and it idles low (<500RPM) and unevenly. I've previously had the car surge while idling when warming up, but it doesn't anymore (bad idle air control valve?). Car accelerated fine at all temps before I cleaned up, and car still idles and accelerates fine while the temp is cool and car hasn't warmed up all the way.

I've made sure that under the hood is dry, but I'm guessing that water got somewhere (spark plugs?). Either that, or the issue I was experiencing with the throttle body/idle air control valve has manifested itself into this problem. (How hard is it to replace the idle air control valve?)

Between the car still intermittently getting warm, and the sluggish acceleration, the car is driving me nuts! Any and all suggestions appreciated.

Thanks again!

MrFatbooty

It's possible you got some air into the cooling system which would explain the cooling problems somewhat. Your idle problem could be caused by either a bad IACV or a bad fast idle thermo valve (FITV). If you could list the *exact* symptoms you have with your weird idle we could make a more thorough diagnosis. Exactly when the idle is weird, how it's weird, when it stops, and at what temp this is all going on would be useful.

Ranmatchi

Well, after doing some more indepth research on the board for similar symptoms, I found you (MrFat) posted in a similar post with some scans from the Helms manual regarding the throttle body area, as well as bleeding the coolant system. So, I cleaned out all the carbon in the TB(tons of it...160K miles worth!) and changed the spark plugs (looked like they have never been changed!) with some platinum 2 tips. Topped off the coolant system at the radiator while the car was cold, and put some into the overflow bottle. Car started up and idled like a champ! Car warmed up, fans came on, and accelerated fine when warm, probably better than before. Turned off the car and started it back up, and it started just fine (no low idle, etc..). My guess is that a combination of dirty TB, old spark plugs, and low coolant created the symptoms I was experiencing. Could also be that some water got into the distributor or someplace after I cleaned and it dried out by the next day.

The problem's not solved all the way, though...I can still slightly smell coolant in the cabin when the car's running and with the fan on, and the coolant level is still getting lower after I drive. No visible leaks, no spots under the hood, hoses and rad cap are fine, coolant looks fine, no oil...took off the head and the oil looks fine (no coolant in it). Don't see any bubbles coming into the coolant bottle, no steam from under the hood. Could it be the coolant bleed valve and the bolt on it isn't tight enough? Or is there a problem somewhere else? My guess is that I should take it in for a cooling system pressure test (can I do that at home?) to see if and where the leak is.

So, thanks MrFat for your posts...they sure did help point me in the right direction. Now I just want to feel comfortable about this coolant problem! (Eventually I need to do a fuel filter too, how hard is that to do?)

Thanks!

90'RS

Did you change the radiator cap? I think it's common sense to do this when changing the radiator and coolant but you didn't mention it as one of the things you had done.

MrFatbooty

Well typically the level in the reservoir will be lower after driving around than when it starts out after sitting for a while. I would definitely pressure test both the cap and the system as a whole. Another convenient page out of the Helms:



You may or may not be able to find an auto parts store that will rent you a pressure tester. If you can, then doing the test is relatively simple.

As for bolts leaking, if anything it's not the bleed bolt (the one by the upper radiator hose). The torque spec on it is only 7 lb/ft. You may have something leaking out of the drain bolt, it needs 59 lb/ft plus a fresh washer and liquid gasket on the bolt threads.

Ranmatchi

Well, I replaced the radiator cap with the new radiator, so that shouldn't be the issue. I do notice that the level in the coolant bottle is actually higher, though, after driving. However, the cap on the bottle doesn't seal all the way...so I don't know if not having a sealed cap on that makes a huge difference? I checked the drain bolt but I can't tell if there's a leak there, however there's no steam. I'll call to see if I can get a pressure tester and continue to check for any other odd signs. (BTW...what are the signs of a cracked head/block...I had someone tell me at one point this was possibly a problem??)
Thx!