Stuck in Nashville...

[TecNickal]

Well did some testing. Drove 10 miles on I-65 south. I managed to keep 65-70 MPH. The car did 220-225F. Ambient temp was nearly 90F, low humidity.

Sitting still, with a small load on the engine, it hit 240F. I shut the car off, and the overflow tank took on air bubbles. It eventually overflowed - cap never blew though The AC was off for all of these tests.

I am going to assume that when the block overheated, it sent a bunch of crud into the rad and is now clogging up passages.

I will install a Policy/Towing heavy duty fan clutch from AutoZone and a new Spectra radiator tomorrow. I hope that'll take care of things tmrw. This has been an expensive adventure - I really want to drive 7 hours back to Columbia SC (home).

[GM_Guy]

Bubbles blowing is usually not a good thing. Before you spend money on a fan clutch, did you verify how it behaved when the engine is shut off?

Alex.

[BuffaloRider]

I am going to assume that when the block overheated, it sent a bunch of crud into the rad and is now clogging up passages.

Makes sense to me. I had this big fuckup last year where my car overheated and busted a coolant leak from my timing chain cover because I had installed a tefba filter (inline coolant filter in upper radiator hose to catch gunk) which had been completely clogged. I checked it regularly and there was only little bits and pieces every now and then, so I'd go longer without checking it. But when it overheated I checked the filter and it was packed so full of shit I couldn't believe it. It was like once it started to get clogged it began overheating, then the heat kicked up more gunk until suddenly I'm on the side of the freeway cursing my forgetfulness. And this is after replacing the radiator, heater core, and all the hoses, so it kicked up all that shit just from the block.

And if your heater core is all full of shit it would make sense that some air could get trapped up in there and cause a bunch of trouble after refilling. Don't know what to say about those bubbles though... Still though, sounds like you're cooling system might be as fucked as mine. Flushing helps keep it under control.

I flush my car as much as I flush the toilet. You decide what that means.

[gadget73]

how old is the radiator? Sometimes they just get smegged up with crap and don't work well. Crusty stuff on the ends of the tubes are usually a solid clue about that. Not using distilled water with the green juice (or premix coolant) will make it do this too, so will running straight water. I can't use my water here, its got so much nasty in it that I'd just ruin the radiator.

Backflow the heater core with a hose while you've got stuff drained. It may blow some of the crud out. Normal flow is from intake to core, and then from core to water pump. Not sure which way your hoses happen to orient, and it doesn't matter very much, but hook the garden hose up to whatever hose is going to the water pump to back flush it.

[88grandmarq]

still stuck? I am in murfreesboro if you need help.

[TecNickal]

Actually got it fixed today. The radiator was clogged with rust. When the engien overheated, it pushed all the coolant with rust into the rad. The rad got clogged from the rust, and coolant could not flow well through the rust.

Installed a new rad - all is well now. Car runs ok, and doesn't overheat.

[DerekTheGreat]

Derusted, cool. I'll add this to the knowledge drawer for cooling solutions.

[BuffaloRider]

In the original post, under notes, you said "new radiator". Are you telling me you bought a new radiator, and it's now clogged to the point where it's overheating and needs replaced? How old is the clogged radiator?

Either way, it's good to hear that you're mobile again.

[TecNickal]

I installed a new rad around Thanksgiving. The car was operating temperature wise just fine. Never had a check engine light. I let the car sit for 2 hours with the air on, in the sun, hood closed. NEver overheated.

So when I boiled the block, all the rust and crud removed itself from the block and by way of the water pump got pushed into the rad. Since the rad has passages as thick as a credit card, it got clogged up with the silt, rust, etc. So no real cooling was happening.

Car is much happier now.No more scary driving.

When I bought my 91 I put in a new rad, a new water pump, a new thermostat and replaced all questionable hoses.

On the 87 it all "looked" ok. I was clearly wrong.

So from now on, unless I have documentation, I will be running a flush kit on all new vehicles on the property - then they will all get a new thermostat, and all questionable hoses replaced. If the water pump is not recent, I'll do one too. not worth it otherwise.

When I get back, I need to fix the timing.

[gadget73]

If its not that old, its possible you can fix the recent radiator with a back flush. I did mine when I had it out for the cam swap, and a bunch of crap came out. I had no cooling problems, and still don't, but I'm sure I did it some favors. I just used the garden hose and fed water in from the outlet end to force it to run wrong-way round. If that won't get it, you can often clear them by letting it lay in the sun while full of white vinegar to dissolve rust and such.

[TecNickal]

Oh yes. I'll flush and back flush the rad. And verify it. Keep it as a spare or for another car.