Over heating problem on 92 LY

[92landyacht]

Been having a problem with her (1992 LY 36' w/454) running hot since I've had her. Now planning on doing somethings to try to remedy the problem.

First: Here is what I've noticed. Seems to run hot on mild hill climbs and in city traffic. OK if I run her in 70 degree conditions but once I'm in the mid 90's it's a real struggle to keep the temps out of the red. Especially at lower speeds.

I've replaced the thermostat (165 degree) and radiator cap (16psi) with no real change. Coolant is clean and green.

First course of action is to hose down the radiator from the inside out in an attempt to flush any debris that may be logged in the radiator fins. Just got the dash AC working so I don't want to mess with removing the condenser. Also plan on replacing the bottom radiator hose and drain/fill with known fresh 50/50 coolant.

Also planning to replace the fan clutch since I never hear it come on. Anyone done this without having to remove the radiator? I can also see the bolts that mount it to the water pump through the curb side wheel well. Any tips on the replacement. I was planning on doing it from the doghouse and just leave the fan inside and pull the clutch. Then reattach the fan to the clutch while inside the radiator shroud and then attach the assembly to the water pump.

Any assistance would be greatly appreciated.

[bigjohnn]

The rad is pluged-up.End of story

[bwoodtx]

I would tend to agree with bigjohnn. Take an infraed temp gun and verify your temps.

Also, check the temp at the top of the radiator and the bottom-should be a 10*-20* difference. You have an a/c condensor, a trans cooler, and the a radiator up there. Radiator is the LAST thing to get air. Take the time to diassemble, you dont have to break hoses loose and clean all three GOOD. Should sovle problem unless you have something going on in the engine.

[92landyacht]

Originally Posted by bwoodtx

Take the time to diassemble, you dont have to break hoses loose and clean all three GOOD. Should sovle problem unless you have something going on in the engine.

So I don't have to disconnect any of the condenser lines to get to the radiator? Can it be just flipped up or something?

My plan was to clean out any debris between the radiator and condenser but was concerned that I had to disconnect the condenser hoses first before I could gain access to the radiator from the front. Freon 12 is not easy to find and not cheap. I have no method of doing recovery.

The fluid in the radiator has always been clean and green with no signs of debris. Engine coolant passages looked very clean when I replaced the thermostat as well. No signs of rust or scale. Was planning on doing a radiator flush though. The coolant may be too much anti-freeze. Was a little thicker then expected. Previous owner may have very well put in 100% anti-freeze instead of the 50/50 dilution recommended.

The reason for the fan clutch replacement was due to the lack of any signs of engagement from initial start to high temps readings. No increase in sound what so ever. Although that could be a lack of air flow through the radiator.

[pago cruiser]

We also have the 454 in our 96 LY30.
When the fan (clutch) kicks in, it is quite noticeable.
WHOOSH!!!!!
For lack of better words.
Once it does kick in, the temp gauge responds rapidly.

[SpletKay06]

It the fan clutch not the radiator, if that was the case it would have an overheating issue all the time.

[92landyacht]

Originally Posted by pago cruiser

We also have the 454 in our 96 LY30.
When the fan (clutch) kicks in, it is quite noticeable.
WHOOSH!!!!!
For lack of better words.
Once it does kick in, the temp gauge responds rapidly.

No WHOOSH sound at all. I'll do the cleaning and flush but probably replace the fan clutch as well.

[Paul Dobbin]

I think bigJohn nailed it. These old radiators get plugged inside & out where you can't see it and cause you to run hot. Dirt that blocks fluid inside and dirt that blocks airflow outside is common with age.

[pago cruiser]

Just thought of something else. Awhile ago I remember a thread on this forum where the inner spring reinforcement of the lower hose was corroding enough to cause rust to slow down coolant passing through the hose. Tried to find it just now, but could not. Might want to check there; or try searching with some different ordered parameters. Unfortunately, the search engine on this site ... um... ah... is not very efficient.

[TomKirk]

If you've got a 165 degree thermostat and you're still overheating, something's going on.

1) Clogged radiator - not just the inside, but outside as well (inspect cooling fins closely). Have you got unimpeded air flow??
2) Impeller blades on water pump may have rusted away. This happens, especially in a caustic cooling system environment.
3) Weak fan clutch

Something to keep in mind: When you fix one thing in your cooling system, the next weakest link (in the cooling system chain) will be the one to fail. So be prepared for that. As a matter of prevention, plan on replacing radiator hoses and heater hoses.

BTW - When you drain the coolant, don't just pull the lower radiator hose, pull the 1/4" pipe plugs on either side of the block. Those plugs drain the water jackets. You should also drain heater core, coolant reservoir, and lower part of the radiator (there should a plug for that). Drain as much coolant as you can while you can.

Carefully note condition of old coolant (Don't just look at it. Give it the sniff test. Compare with new coolant). That'll give you some clue as to what's going on inside your cooling system. Ugly coolant means ugly cooling system. You may hafta flush (more than once).

Tom

[guskmg]

454 GMs are notorious for clogged radiators and bad thermostats. Take the radiator to a radiator shop and have them boil it out. They may have to re-core it. Also, I had a friend who rebuilt his 454 only to find out later the overheating was due to a faulty thermostat. My experience is that you need to do this every five years. On the newer GMs, if you change their anti-freeze every five years with a flush you would be OK. Then, happy camping from then on.
guskmg

[Naper]

Thermostat has no effect on overheating. Once its open, its open. The thermostat is there to help the engine warm up faster and keep it warm in cold weather.
Overheating is usually air flow or water flow.

[Grosspoluter]

I to went through my cooling system on my 1984 airstream 345, 454 V8
Doing a little research I found posts on other sights that said "the 454 loves the heat"
I say that's B.S.
I drained the system, back flushed the system installed a new 165* thermostat...
But also was informed that the temp sending unit on the 454 is on the head not the intake manifold... (Head is always hotter)
So I installed a aftermarket temp gauge (installed in upper hose) and there is quite a difference 220* head 180 hose
I finally got it running cooler ditched the antifreeze for "water wetter" (I think it's manufactured by red line products)
All was running perfectly, until a few weeks ago, threw a belt and overheated 😕
(Read some of my more recent posts)
Hope some of this info helped

[Grosspoluter]

Forgot to mention...
Cooling system needs to be drained and antifreeze added for the winter
DO NOT leave the water wetter in over the winter!

[92landyacht]

So, does anyone have suggestions on the best methods to replace the fan clutch and clean between the AC evaporator and the radiator?

[bkahler]

Originally Posted by 92landyacht

So, does anyone have suggestions on the best methods to replace the fan clutch and clean between the AC evaporator and the radiator?

Fan clutch can be replaced while laying on to of the engine. I've done it twice. It's not fun but it's the only way to do it that I know of without removing your radiator.

Reading through this thread you basically have two things you can try. The easiest by far is replacing the fan clutch. The ACDelco unit is about $110. I wouldn't buy a cheap one from a parts store because they are generally a generic unit and there have been a lot of people complaining that the cheap ones don't come on at the right temperature. Your last choice is to replace the radiator.

Personally I think you might be a year or two by replacing just the fan clutch but in the long run you will have to take the radiator out and at a minimum have it cleaned but if it were me while it's out I would re-core it which means you don't have to worry about it again for a LONG time!

[92landyacht]

Any suggestions on how to remove the radiator from a 92 P30 based Land Yacht? Can it be dropped down through the bottom? I'm really wanting to get this done without dumping all my fresh Freon 12.

[bkahler]

Originally Posted by 92landyacht

Any suggestions on how to remove the radiator from a 92 P30 based Land Yacht? Can it be dropped down through the bottom? I'm really wanting to get this done without dumping all my fresh Freon 12.

I'm not really familiar with the Landyacht's but it probably has the horizontal radiator which has to come out the front. The radiator is wider than the frame rails. Prior to 82 or so the radiators were tall and skinny and could slip through the frame rails and out the bottom.

Sorry to be the bearer of bad news.

Brad

[garypk]

Originally Posted by 92landyacht

Any suggestions on how to remove the radiator from a 92 P30 based Land Yacht? Can it be dropped down through the bottom? I'm really wanting to get this done without dumping all my fresh Freon 12.

Cant you pump down & recover your r 12? You just let it go?