454 running too hot?

[Senior Chief]

We just replaced the non-working dash temperature gauge in our '89 P30 Southwind with a fancy Glowshift gauge. The sensor on the new one is screwed into the block in the same orifice the original sensor for the electric fans used (PO changed to a dash switch for these), at least according to the chassis manual.

We tested the new sensor before installing it with a very accurate digital thermometer up to about 200 degrees, and it was within a couple degrees.

We have been stuck here for the past few weeks waiting for an AC part (shop slow anyhow, but ; ordered; came; wrong; re-ordered (fib);re-ordered (truth) It will be here on Wednesday! ) but in the short amount we've driven it since replacing the gauge it seems to be reading about 220 degrees after it warms up. This is on fairly flat roads without the toad.

We flushed the radiator this spring and it has fresh 50/50 coolant. Its got a fair air dam around the radiator, at least on the top and sides (need to fill a gap on the bottom) and a new 180 thermostat. No dash AC.

As stated previously, the electric fans work off a dash switch now, but my understanding is they don't assist any once you're over 35 mph.

We'll be heading south to Texas from here; I'm concerned that running temps are on the high side.

Any thoughts/advice??

[awarnes]

I have an 87 Allegro with a 454 and had some overheating issues this year. It was a simple fix and solved all the issues.
1. Was overheating at 60 mph and good at 35 mph. Belt had come off and wrapped around the flywheel. Had belt replaced and all was good.
2. Had radiator flushed and all system pressure checked and had to continue to add fluid for about 100 miles.

Now the fan clutch kicks in at midpoint and no overheating issues. Went over the Cascade Mtns and into hot weather (95) and not issues. Had a 7+ mile climb up the Columbia River Gorge and was passing all sorts of vehicles at 60 mph and it was great.

I don't know if this helped or not, but I also have a local mechanic that knows more about my MH then the specialist I took it to this year for the brakes and our guy charges 1/2 the rate. I have even decide to keep it longer and makes some modes because I know what issues are there.

I hope you are able to solve your issue and have fun.

Good Luck
Arnold

[Senior Chief]

We also had a crackerjack local mechanic, but he wasn't able to get the MH physically inside his shop; he was getting up in years a bit and didn't want to work out in the weather on the old girl. I can't say I blame him.

Belts and hoses are all new this year; no issues there.

[Billieg]

I also have a 454 and I watch my temp go to 220 running down the road with the AC dash air on. I checked the manual and it says 210 - 220 is normal but hit a hill and I have to turn off the air so it doesn't go over 250. I wired my fans direct so when the key is on so are they and this helped a bit. I don't have an answer except maybe to change the radiator to a heavy duty one which I'm looking into.

[whem2fish]

seinorcheif its over 100 in texas ill be waiting to hear what you find. i run a stuart warner stage 3 gauge. now i pull a 4 door chevy truck i run 210 - 200 on a long grade i turn off ac now i do have a large air dam under radiator

[whem2fish]

also will you be south of dfw

[POPPASMURF]

Maybe go look for a radiator out of big ol tandem gravel truck that used the 427 chev. gas engine. Those trucks could work day in day out in any weather without problems. If nothing else, it'll give you an idea of how much radiator you need.

[Senior Chief]

Quote:

Originally Posted by whem2fish also will you be south of dfw

We'll be heading down to Livingston TX first, and then over to El Campo.

[Senior Chief]

Quote:

Originally Posted by POPPASMURF Maybe go look for a radiator out of big ol tandem gravel truck that used the 427 chev. gas engine. Those trucks could work day in day out in any weather without problems. If nothing else, it'll give you an idea of how much radiator you need.

That's a good idea. We've talked about swapping out the radiator (getting it re-cored seems to be more expensive than a new one ) but it just hasn't been high up the food chain.

[grumpy14]

check your cap first around 14# is best-the higher the cap the higher your bolling point will be,we run 24# on our race car 250 and don,t boll

[Senior Chief]

Quote:

Originally Posted by grumpy14 check your cap first around 14# is best-the higher the cap the higher your bolling point will be,we run 24# on our race car 250 and don,t boll

Thanks, I believe our cap is radiator 16#; too hot outside to go out and check it now

[BA-in-Mich]

If it is the original radiator from 1989, recore or replace it. Chances are the fins are coming loose from the core pipes and it is probably getting corroded up inside. That was the issue I had for years on my "90" . I was in denial for almost 10 years. Best money I ever spent on it. ($500 recore)
The other thing also was that is was a 4 core that had 3/8" cores. After rebuild it has 5/8" cores but yet still a 4 core. Runs 180* always

[mavric65]

Quote:

Originally Posted by grumpy14 check your cap first around 14# is best-the higher the cap the higher your bolling point will be,we run 24# on our race car 250 and don,t boll

this is a true statment i also did this when i raced but make sure your cooling system can handle the added pressure since i have seen people try this on old radiator and they cant handle the pressure and pop the tanks off the core....

Just for thought

[ga traveler]

I can't say for sure about a 1989, But the 1995 I had was normal to run 220 degrees. This is according to chevy manual.