Bullydawg

iTrader: (7)

I might be buy an 89 Iroc 350 TPI w/ 122k miles... but it overheats.

What could it be? It runs then it starts overheating and it starts boiling over in the overflow tank?

Guy said he replaced the Thermostat, radiator, and fan is wired to a switch...

The water pump doesn't make any noises nor does it leak...

Could it be the Head Gasket? It didn't smoke at all... Ill check it oil tomorrow.

Timing?

tom3

Wonder if it might have the wrong water pump on it, reverse flow needed. Does it overheat quickly or out on the road?

8t2 z-chev

most likely a circulation problem is the cause,possibly a
bypass problem causing no circulation past the thermo
stat,not allowing the thermostat to open until engine
gets real hot-after starting the engine cold,the heater
hoses should get hot first,then the radiator hoses should
start to heat as the thermostat opens.

Bullydawg

iTrader: (7)

So chances are it is something simple? He said it might be the water pump, but I am not sure, he said he didn't replace it... It just doesnt make any bad sounds, or leaks...

What could be the worst that is wrong with it... He said the coolant backs up into the reservoir, sorry. It doesn't boil.

He said it takes like 20-30 minutes for it to overheat, so I am assuming on the road... He said he put all new gaskets in the engine? Any possibility he didn't put the head gaskets in correctly? Or would it be really obvious it is the head gasket?

y84pauloflondon

1) Did you check to see if it has the air dam under the car?
2) Do the fan(s) ONLY come on with the switch?
3) Are you able to check the condiction of the coolant, is it a proper mix? (50/50)
4) Did the owner/tech run all the Air Pockets out of the system?
5) Could it be a bad thermostat? It only takes 1 overheating to wreck a CHEAP thermostat!

y84pauloflondon

Oh, Rad Cap....not holding pressure!!!!!!!

Bullydawg

iTrader: (7)

I think I am going to pick it up... The guy didn't know how to read the odometer... haha... he thought it had 228k miles... I looked at it and it is 122k... haha... It has rolled once I believe.

Is it worth the chance? 89 Iroc Z 350 TPI black... clean body no rust... little dings here and there? Reg is current... Guy wants 1k... Idles a bit high, but I think it is it IAC.

Gregzz4

Great tips paulo
Simple things to keep in mind, barring Engine problems.....
City overheating usually points to lack of Air Flow. Causes can be externally plugged Rad/AC Cond, slow/late Electric Fan Switch ( coated with sludge/tired ), tired Electric Fan/Clutch Fan, and slipping Water Pump Impeller ( rare ).

Highway overheating usually points to lack of Coolant Flow, although as paulo pointed out a missing Air Dam/Valance can also cause this ( the Dam directs Air up to the Rad to make up for the lack of Air Flow through the small Grill ). Cause is usually an internally plugged Rad, although a slipping Belt or Water Pump impeller can also cause this.
There are many other things which may cause either of these situations.
I have a list posted @ work just to show Customers how many causes there are, including sticking Brakes, slipping/overheating Trans, bad Bearings, anything to make the Engine work harder.
Give me more info and I'll gladly help. I'm a 20yr Rad Guy
Greg

Bullydawg

iTrader: (7)

What are the chances of it being the head gasket?

And what would the cooling/engine act like if it was a blown head gasket?

Gregzz4

Head Gasket leaks can be very easy to identify and also very tricky. I can't really answer that for you in any way that will help you decide whether or not you buy it.
For the obvious/continuous leaks we use a kit which detects Exhaust in the Coolant, but years ago we had a 64 1/2 Stang that only leaked halfway to fully warmed up, then the leak went away.
Usually Head Gasket leaks cause the Coolant to warm up faster than normal, in the first few minutes. Keep in mind that the Exhaust Gas is hundreds of degrees hotter in the Cylinders than the Coolant temp, so it only takes a tiny, tiny pinhole to increase the Coolant temp.

Don't forget to check what paulo said. Is the Air Dam there? Is the Rad Cap holding pressure? When it boils into the Bottle what is the Temp when that occurs and which hose is hotter, the Top rad hose, or the Bottom? Don't Burn Yourself!!

I know I haven't helped you decide, but maybe you could go look at the car and, from a cold start, warm it up and road test it. Make notes of the temps, when it overheats, if it cools down some or at all, what temp it's at when the fan cycles if it's Electric, what temp it's at when it boils in the bottle and so on.
Post it and I'll have a look.

Bullydawg

iTrader: (7)

I doubt it is a head gasket... Chances are it is something small... I mean the car runs great and sounds good.

kowboy59

iTrader: (8)

just had my headgasket go. just because theres no smoke or water/oil mixtures does not mean ur safe. It can be slowly going blowing the exhaust into the coolant which would cause a overflow or the impression of boiling into the resevoir.

you can get a carbon dioxide?? checker and see if there is carbon in the coolant

y84pauloflondon

I would start by checking the small things first, its the cheaper way to go.

This my sound dumb, but you mentioned that the prev. owner changed the rad. Did you check to see if the tech hooked up the fans prorperly? Are the fan(s) spinning in the right direction????

Did you check to see if there is any coolant in your oil? If there is, your oil will look "milky"!

Bullydawg

iTrader: (7)

I ended up passing on it so I can fix a ton of little issues my car has... The Iroc blew alot of white smoke. I think it was a head gasket issue... The guy selling it is going to school to be a honda tech, so I am sure he checked all the little things first.

UKPROCHARGEDGTA

had this with one of my customers, fan connected back to front (blowing air forward instead of sucking through) caused overheating on highway
worth checking if anyone has this problem

ponykiller1187

im having the same problems and its killing me and i see your car ran a 13.1 with a 1.8 60ft i ran a 13.0 with a 1.6 60ft and no one believes me i have a 87 camaro with a 350 and a crapy exhaust

bcmag

when does it overheat...at idle or while driving?

hotbird89

I had the same issue before as well. There were several issues with the car too. The first issue was the air dams under the car. They were ripped off- replaced 'em. Still overheated. Then I got into the large repairs. The A/C condensor fins were damaged enough that there was almost no air flow. I replaced it as well. This helped the car alot- it took alot longer to overheat, but it still did. While I was replacing the condenserI noticed that it had the stock radiator, fans, and control system (that didn't always work).

I picked up an aluminum 4 row radiator from ebay in a kit that came with 2 2800 CFM fans as well. I also picked up a compressor works part number 733647 fan control. To mount the radiator I had to do ALOT of modification to the radiator mounts. the radiator was the stock width and hieght. The depth however was WAAAAAY deeper (almost an inch and a half). I grabbed 2 pairs of GM weatherpack connectors for the fans, mounted them to the radiator. While I was in there I dropped in a new water pump- nothing special, just new. Now when I run her, be it in 10 or 95 degree weather the cooling system stays right where it should. The fans cycle on and off and I'm running a 185 thermostat with no issues.

This was not the cheapest repair on the planet, but it was well worth it since the old gir runs right. These are just a couple thoughts for yah. From personal experience (over 15 years working on F-bodies) the problem isn't anything exotic. The radiator and fans has always been the biggest problem, and most people are too cheap to replace them with what the car needs. Good luck, and H*ll yes the car is worth it.