puzzled...head gasket/cracked head??

[gse2schmidt]

Just bought my third quad4....95 grand am 75K miles

It runs smooth but.....

Took this one home did fine for the first little bit, took it to work 10 miles....Ok. Then on the way home I noticed it was running a little warm, then a little warmer.

Next day I was off and tried to get it to repeat the problem. It warms up at the usual ramp rate then after while it hangs around 220 then drops a little. Fan kicks on and off ok then it seems to just slowly start climbing, and then if I head to the freeway it really gets up there. I shut it down before it gets to the red, got the red light once too...its boiling.

Tried flushing the cooling system, changed the thermostat. The cooling fan comes on and off OK. It will sit and Idle all day long no problems, but once I start putting a load on it it starts heating up.

When the cooling fan kicks on it puts out warm air for about 5 seconds and then blows cool but the engine is still over 220.
Thought it might be a restriced radiator but my mechanic flushed it and he said that he got good flow and no junk out of it.

I checked the weep hole on the water pump and it's spinning OK. No stripped splines 75k I would hope not.

Now he is conviced that it is a blown head gasket or cracked head. If it is there is no water in the oil.....no white smoke....if it sits at an idle I don't see any bubbles in the overflow tank. If the engine is over 220 I see some bubbles sort of with the lid is off mostly from the rear vent line to the overflow tank.

Anyone out there had one like this? was it the gasket or the head? What caused this? Just one day its time to go or did someone run it low on coolant or something? Could it be something else. Hoping that if I take the head off I can get it magnafluxed with the valves still in and get her back together without a new head? Any problem areas to look for on the head?

[scaviola]

Originally Posted by gse2schmidt

When the cooling fan kicks on it puts out warm air for about 5 seconds and then blows cool but the engine is still over 220.
Thought it might be a restriced radiator but my mechanic flushed it and he said that he got good flow and no junk out of it.

I checked the weep hole on the water pump and it's spinning OK. No stripped splines 75k I would hope not.

I had the same problem about a year ago on my '93. If your radiator isn't restricted, but the fan blows cool air, it still means that the water isn't flowing well. In my case, I took it to the guy who had previously fixed my clogged radiator. He replaced the water pump. He mentioned that while he had everything apart, he noticed a lot of sealer/stopleak plugging everything up and that he flushed the whole system several times to get it all out. (Why it didn't come out the last time he flushed the system is anybody's guess) So, the pump might have been good after all, but it's hard to tell since he removed any possible obstructions as well.

[gse2schmidt]

I'm still getting used to this pumps go bad thing...

I had a pump go bad in my 1994 SOHC it sounded like the timing chain was coming apart, when in fact the bearings in the pump were shot and it puked antifreeze into my crankcase. Changed the pump all noises went away and the engine even survived the coolant getting mixed in twice.

The pump is just a metal star that spins, i'm sure its spinning, how can it NOT pump water??

interesting that the flush did not work for you the first time might be worth a second look for me.

How did your mechanic NOT suspect a head gasket?

[scaviola]

Originally Posted by gse2schmidt

How did your mechanic NOT suspect a head gasket?

Well, at 220k miles the head gasket is basically a ticking time bomb... He told me he did a pressure test because he was worried about it, especially since all the sealer had been flushed out, and there was nothing wrong!
To clarify, the first time I took it to this guy was because the radiator was clogged. All he did was unclog it.
The second time was when I was having the symptoms described here (about a year later). He had it for 2 days and tried very hard to make sure the car would never overheat again, which included changing the water pump (supposedly bad) and several flushes of the system.
Whatever my problem actually was, it wasn't the head gasket. If your guy suspects the gasket, he'd better have a good reason to convince you - that's a darn expensive job on the Quad 4.

[gse2schmidt]

Taking it to a mechanic that has a hydrocarbon gas analizer to tell if those mystery bubbles are from a gasket leak or just places the coolant is starting to boil.