Overheating... '94 Rodeo 3.2

[jmeyert4a]

Hi all... my Rodeo has RECENTLY been overheating... low speed under load (off road) or low speed in traffic w/AC on.

10 mos. ago we pulled the engine and replaced a leaking "0"-ring behind the head, and we replaced all belts/hoses. Engine was VERY clean, no evidence of sludge/scale, etc. (Car has a chinsy plastic radiator, BTW, but it worked BEFORE!)

Was previously able to off-road and pull a horse trailer, no problem.

Since the end of March I've been having problems.. I've replaced the fan clutch (after market (NAPA)), thermostat and radiator cap.

Problem definitely seems to be airflow related... Going slow up a SLIGHT grade in afternoon traffic it overheats, going up a much steeper grade at 50MPH in 3rd gear is OK...

THOUGHTS/SUGGESTIONS?

Jim

[amigo-2k]

Flushed it lately? radiator full of mud? maybe the Napa is not up to OEM standards?

[jmeyert4a]

Originally Posted by amigo-2k

Flushed it lately? radiator full of mud? maybe the Napa is not up to OEM standards?

Thanks for the quick response!

Yes, I HAD flushed it back when we did all the work... Was Really clean then... Flushed it again today... didn't see ANY evidence of anything other than good clean Prestone...

BUT I MAY have found the problem. When I was flushing it, (thermostat removed, garden hose in lower rad. hose), when I turned off the water and started the enging, only a trickle camo out of the bell... I reved up the motor a bit and the trickle was still a trickle... Shouldn't the water pump have PUMPED out some volume of water?

Thanks for your help!

Jim

[jmeyert4a]

Originally Posted by jmeyert4a

Thanks for the quick response!
...
BUT I MAY have found the problem. When I was flushing it, (thermostat removed, garden hose in lower rad. hose), when I turned off the water and started the enging, only a trickle camo out of the bell... I reved up the motor a bit and the trickle was still a trickle... Shouldn't the water pump have PUMPED out some volume of water?

Thanks for your help!

Jim

OK... forget that last. When I thought about it overnight I realized that with the system 'open', it couldn't draw water up through the top hose and into the motor...

Jim

[tinyejp]

Things to check-
Radiator cap- if it isn't causing pressure, the system won't work properly.
Ignition timing- You can't change it on these things, so I don't know what to tell you there.
Temp. sending unit- could be telling your ecu that it's fine, not turning on the fan and stuff.
Insufficient coolant- I know, I know. It's silly, but sometimes it happens.

HTH!

[heritage72]

How big of a job was the fan clutch? I am having a similar problem and thought I would start there...

[jmeyert4a]

Originally Posted by heritage72

How big of a job was the fan clutch? I am having a similar problem and thought I would start there...

Good morning... Not too much trouble... easier THIS (second) time...

REmember to loosen the alternator belt... (lets you turn the hub, and keeps the flange aligned). Remove the top hose and the fan shroud (4 clips and 2 or 3 push-pins)... does't seem to be any advantage to pulling the radiator, since I could only get an open-end wrench (12mm) on the nuts any way.

With the shroud out of the way you can change all of the belts and it might be the time to get new hoses...

As for 'statring there', that's what I did, but it didn't solve my problem... Take Amigo 2K's advice and get one from the dealer... (The NAPA one cost me about $140... )

Good luck,
Jim

[johnsm]

I had a similar experience with my previous vehicle. I had to replace the radiator. Mind you mine was metal and ruct had clogged the cooling system.If it is not the rad, you may have bought a faulty or incorrect thermostat.

John

[NMRODEO]

So my 95 is acting the same way in traffic. I have replaced the therm and the cap and the results are a bit better but still creeping up to the redline. The local mecanic said it cold be excessive build-up on the motor or just a faulty gage. how would i know if I have to replace the radiator (just had it flushed)? What about a high-flow Fan?

[jmeyert4a]

Hi all... And a BIG THANKS to all of you who offered advice... In my case it WAS a plugged radiator just like Amigo2K first suggested...

I'd flushed the system and EVERYTHING 'looked' squeeky clean... But, after changing radiator cap, thermostat, all hoses, water pump (timing belt while I was in there) and not one, but two, fan clutches... It was STILL overheating at low speed under-load.

I took it to a friend who owns a radiator shop... He had me run it for a few minutes then TURN IT OFF... He reached in, in front of the fan and felt across the radiator... He had me do the same... At the area below the inlet, it was cold... as I moved my hand across it got warmer, then hot on the outlet side... about half of the radiator was plugged.

I bought a new radiator and, presto, no more overheating problems!

Oh, did I mention... TURN IT OFF before reaching in to feel the radiator?... Just a reminder...

Thanks again folks!

Jim Meyer

[NMRODEO]

LOL, I wont forget. New radiator it is! same problem here

[NMRODEO]

WOW who would have thunk it! I replaced my radiator and presto, good as new!!

Thanks for all the advice guys!