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Jarog · 06-01-2013, 05:46 PM

Quote:

Originally Posted by steveclv

My 1984 Monaco had the 454 carb engine and always ran hot and was designed to do so for emissions - spec was 225 and 240 was acceptable.

However, as road speeds have increased over the decades, I found that the a good size hill would bring it over 250 and that was too high for me to feel comfortable even though I was told that it was perfectly normal.

I ended up going to a 5 core radiator instead of the original 3 and it made a huge difference. If you do go this way, they use the 195 thermostat with it.

After I did that, I could run full throttle up a long hill and still keep 240 at the top.

Of course, I also replaced all of the vacuum lines and made sure that the distributor weights were free to move and lightly oiled.

Mine wants to run at 240 when idling. If I put it in neutral and spool up the engine the needle drops to about 230 225 or so.

BA-in-Mich · 06-01-2013, 05:46 PM

What are the details about the radiator? Oem ? Recored? Aftermarket? Also does this have a butterfly heat riser?

Jarog · 06-01-2013, 06:05 PM

Quote:

Originally Posted by BA-in-Mich

What are the details about the radiator? Oem ? Recored? Aftermarket? Also does this have a butterfly heat riser?

Not sure what a butterfly heat riser is????? Radiator wAs recored. I didn't replace the ac condenser. It's the only old part I put back on. It didn't look clogged but I suppose it could be. Hmmmmmm. Wonder if I should take it off and take a drive and see how that works.

steveclv · 06-01-2013, 06:42 PM

Who did the recore? It certainly should not be getting that hot at idle - I suspect either a faulty water pump, an internally collapsed hose or a faulty radiator.

Timing and mixture will not be the cause of overheating at idle - they come into effect under load - the engine is generating the least amount of heat at idle and the fact that when you rev it, the engine fan is pulling 4000cfm of air through the radiator and getting the temps under control points at the radiator as being the primary problem.

To check the head gaskets, if you top the radiator up and then put the cap on, warm the engine up (not hot) and then carefully remove the cap, do you see bubbles or significant loss of coolant?

If you can afford it, I can't recommend a 5 core rad enough - it will fix the issue once and for all - mine cost me $500 cash.

BA-in-Mich · 06-02-2013, 05:27 AM

I can't remember if that is old enough to be old school but they use to have a bi-metal coiled valve on the drivers side manifold it used to block off some of the flow to heat the engine up quicker. What would eventually happen is it would freeze in a closed position and would overheat the motor. Also did they recore the radiator to the same thing that you had? Mine was originally a 4 core with 3/8" tubes. When I had it recored they kept it 4 core but used 5/8" tubes. With a 180 degree stat, that's where mine runs all the time now. Another thought what about clogged mufflers and or cat converters if you have them. I know some people in the past have had that issue. If it's getting hot at idle, remove the mufflers and cat converters if you got them and idle away and see what happens.

Jarog · 06-02-2013, 07:33 AM

Quote:

Originally Posted by BA-in-Mich

I can't remember if that is old enough to be old school but they use to have a bi-metal coiled valve on the drivers side manifold it used to block off some of the flow to heat the engine up quicker. What would eventually happen is it would freeze in a closed position and would overheat the motor. Also did they recore the radiator to the same thing that you had? Mine was originally a 4 core with 3/8" tubes. When I had it recored they kept it 4 core but used 5/8" tubes. With a 180 degree stat, that's where mine runs all the time now. Another thought what about clogged mufflers and or cat converters if you have them. I know some people in the past have had that issue. If it's getting hot at idle, remove the mufflers and cat converters if you got them and idle away and see what happens.

Not sure but I think mine has this bimetal coil on it. There's something on the drivers side manifold that I can't identify. I'll post pics in a lil' while. They recored to original specs, which I would think should be good enough being that it came from the factory that way. I'm not Pulling a trailer or anything. I've been thinking about the clogged exhaust thing. Gonna peruse that one today. If it doesn't rain on me.

Jarog · 06-02-2013, 07:49 AM

Today's updates ! I installed a 180 deg thermostat, put antifreeze in, put fan shroud on and all that made no change. Took it on a 20 mile trip. While running on two lane at about 45 or 50 mph my temp was about 220 225. Made the turn to get on the highway. Had to wait at a red-light to make the turn and it warmed up to 230deg. Got on the highway and ran up to 60 mph. It hung in there at about 230deg. Ran it up to 65-68 mph and it warmed up to about 235-237deg. I could then slow down to 55 and it would cool back down to 228-230deg. Exited the highway and got stopped at light where it heated back up to about 238-240 deg. After creeping along through traffic ( with the fan engaged) it cooled down to about 225 till I pulled into the driveway. I let it idle till it got to 235-238 deg. When I shut it off the needle spiked up to 250-255 deg. Something weird going in here. This thing behaves like nothing Ive seen before.

Jarog · 06-02-2013, 10:29 AM

Today's idling temp. I removed the ac condenser. I think my radiator recore just wasn't done correctly. Condenser didn't seem to be blocked. At 65mph it ran at 128-130 deg. Is this safe ? Do I still have a problem.

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Jarog · 06-02-2013, 10:30 AM

Quote:

Originally Posted by Jarog

Today's idling temp. I removed the ac condenser. I think my radiator recore just wasn't done correctly. Condenser didn't seem to be blocked. At 65mph it ran at 128-130 deg. Is this safe ? Do I still have a problem.

Sorry. I meant 228- 230 deg.

steveclv · 06-02-2013, 10:40 AM

I agree that the radiator is where your problem lies.
230 isn't going to hurt the engine at all - I am just worried that you do not have enough cooling capacity in reserve. You need a steep hill or two to really test it.

I always believed (and read) that the original spec rad was marginal at best, even when everything was brand new.

Jarog · 06-02-2013, 10:59 AM

Something I've been pondering. This is an aftermarket temp gauge. How much should I trust it? This morning I fired it up and at idle speed. Temp gauge reading. 162. I crawled all over it with an IR thermometer. It was 135 @ the thermostat housing. About 140 where the return comes out of the water pump. The intake was at about 160 degrees. Where should I be checking temp?
This brought me to the conclusion that the radiator wasn't getting enough air flow. If the temp going into the engine is the same as that coming out then something is wrong. I the. Removed the ac condenser coil and headed in down the road. The results are in the previous post.
So the intake was the same temp As what the gauge was reading. Is that correct?

Bilito · 06-02-2013, 11:56 AM

Quote:

Originally Posted by Jarog

Something I've been pondering. This is an aftermarket temp gauge. How much should I trust it? This morning I fired it up and at idle speed. Temp gauge reading. 162. I crawled all over it with an IR thermometer. It was 135 @ the thermostat housing. About 140 where the return comes out of the water pump. The intake was at about 160 degrees. Where should I be checking temp?
This brought me to the conclusion that the radiator wasn't getting enough air flow. If the temp going into the engine is the same as that coming out then something is wrong. I the. Removed the ac condenser coil and headed in down the road. The results are in the previous post.
So the intake was the same temp As what the gauge was reading. Is that correct?

Here is a question, in the morning before you start the engine what temp does the gauge read?
That's a nice looking modern gauge perhaps it is faulty and giving incorrect info on the road. Do you have another gauge laying around to do a comparison?

Jarog · 06-02-2013, 01:52 PM

Quote:

Originally Posted by Bilito

Here is a question, in the morning before you start the engine what temp does the gauge read?
That's a nice looking modern gauge perhaps it is faulty and giving incorrect info on the road. Do you have another gauge laying around to do a comparison?

It always reads zero before you start the engine. One time I saw it go up to 160 then jump to 180. As if it had gotten stuck. I need to check the sending unit.

Brockx · 06-02-2013, 01:56 PM

Quote:

Originally Posted by Jarog

It always reads zero before you start the engine. One time I saw it go up to 160 then jump to 180. As if it had gotten stuck. I need to check the sending unit.

When you turn the key on without starting, I would think it should read ambient this assumes it is electrical. If it is a mechanical (fluid) it should always read ambient.