1985 345 Major Overheating issues

[Toddnazus]

Thanks in advance for those who maybe able to provide insight into our overheating problems...

A couple of years ago we purchased a 1985 345 (gas) Airstream Motorhome. Our unit had 32k miles when we purchased it, and currently has about 35k miles.

After using it successfully on a number of trips, we ended up blowing out the value cover gasket returning to Tucson from San Antonio. The loss of oil we experienced caused us to overheat, but we were able to continue by "resting" the engine and continuing to pour more and more oil into it until we found a very accommodating repair shop who replaced the gasket and got us back on the road.

Once we returned to Tucson, we took it into a RV repair where they went back in, re-machined the heads to eliminate any warping, replaced the bolts etc. to ensure we had a good seal etc.

Unfortunately... we're still overheating... even on flat ground, the temps were still rising to >230 degrees....

The next steps included:
1) added updated additional auxillary fans in front of the radiator (and a bigger alternator to power them).
2) re-coring the radiator
3) replacing the water pump
4) added an oil cooler to the engine
5) replaced the thermostat

While these steps seem to keep the temps lower on flat ground, even small/medium size hills cause the temps to rise to the same levels as previously... Once the temps rise... they do NOT seem to come down until the unit is turned off...

At this point we're investigating having an aluminum radiator built as we're informed that this will allow the coolant to cool more quickly... This is looking like a cost of $1,000 since the radiator is a unique design.

We LOVE this bus and dearly want to be able to enjoy it without having to worry about overheating on EVERY trip...

HELP !?!?!? Has anyone else had difficulties with overheating like this ? AND/OR does anyone have any further suggestions as to what maybe the cause of our overheating ? and/or other resolutions we may want to consider ?

Yours In The Love of Airstream Motorhomes,

Todd

[John Woodrow]

That is unusual. Did the shop that did the head work evaluate the engine to determine if running it low on oil cause irreparable damage? Did anyone verify that the temperatures are not just a gauge / sending unit error?
If you had the radiator re-cored it should cool almost as effectively as a new aluminum one. When the radiator was out they replaced the water pump and thermostat. Did they also replace the fan clutch?
You've spent a lot chasing this issue down to no avail. Seems to me that the next investment should be on some new experts.

[GCinSC2]

Todd,

I really can't offer solid help other than a diagnostic tool that MAY help chase things by showing you actual temps at any spot you can point to. An infrared thermometer. It has so many uses you'll be surprised. I watched a tech confirm a hunch on a low temp issue in minutes.

What about any exhaust restrictions?

[Toddnazus]

Thanks for your thoughts GC, They did confirm that the gauges are working correctly (if I'm interpreting your feedback correctly).

I WILL followup with your thoughts on exhaust restrictions. Could you elaborate a bit more on what this would look like ? and how it could/would impact the engine temps ?

(I'm not mechanical at all... so this is a major learning process for me).

[Toddnazus]

Also thanks for your feedback as well Mr. Woodrow.

We have confirmed that it is not the gauges malfunctioning...

If you don't mind, can you elaborate on what types of "irreparable" damage might need to be evaluated ?

Also, I'm not sure about the fan clutch... but I will follow up with our repair shop. What/how might that impact the cooling ? (I'm a TOTAL non-mechanical person, so I'm educating myself as I go).

Fortunately, this shop is being VERY diligent about their work (not charging us an ARM/LEG for what they have done so far) and also working hard to determine the cause of the overheating as they really don't want us to breaking down again.

[GCinSC2]

Todd,

The temp gun goes beyond what a gage shows from a single point. You can watch the temp change as the coolant flows from engine to cooling system and back. Also great to shoot the inlet radiator temp vs outlet temp to see temp change. Transmission coolant line temp, heater core hose temps.

Then for checking tire, brake and all manor of temp based situations.

Good luck.

[Toddnazus]

Thanks again for your feedback GC !

I'll be discussing your thoughts and Mr. Woodrow's with my Shop on the next call. IF there are exhaust restrictions, would that imply that the "hot air" is not being expelled properly ? and therefore keeping the heat within the engine ? instead of expelling it ?

Todd

[John Woodrow]

It's good to know that your shop is doing their best and treating you fairly.
To answer your question, an engine that is run without oil will ultimately seize up and be ruined, which is generally irreparable. It is not a black and white issue so it's possible that self destruction due to oil starvation had begun but the day was "saved" by your stopping and adding oil. Did it need one quart or several? A teaspoon of oil leaked onto on a hot exhaust manifold will make terrible stinky mess. You'll have to be the judge of how low the engine oil got and together with your mechanics if internal damage is likely. Since they had the heads off they had a good look inside and apparently saw no damage.
The fan clutch is a disk shaped unit that mounts between the radiator fan and the water pump. It is a temperature controlled viscous clutch that engages the fan when things heat up and free wheels when not needed, thus saving gas and horsepower. They do tend to get tired over time and should be replaced when you replace the water pump. They are less that $50. In the event that your fan clutch is bad and was not replaced, you'll have exactly the problem you are having.

[Toddnazus]

Outstanding Mr. Woodrow ! I don't recall having any discussions about the fan clutch, but I will certainly be asking when I call my RV shop again !

To address your question on How Much Oil we put in when it was overheating... we put in multiple quarts (every time the temp went close to 240 we stopped and added more). At the initial repair site, we determined that we were down 1 quart of oil (when the did the first repair of the gasket on the return from San Antonio). So we felt as if we were keeping the level as high as possible while the gasket leak was occurring.

Thanks you again Mr. Woodrow and also CG !!! believe it or not... your comments are actually comforting in that our overheating issues seem to be 1) a bit out of the ordinary and 2) some definite ideas and suggestions for other possible causes and solutions !

Many Thanks to you both !

Todd

[Waipio Rim]

Here's a sample of the temperature gun mentioned above:

https://www.amazon.com/Thermometer-N...rmometer&psc=1

Very handy, I keep one in my glove box. If you want to know how cold it is outside, just point it at the windshield.

One thing to keep in mind: normal operating temperature for this engine per the manual is 190-240 degrees. We have had a lot of the same PM done as you, minus the extra fans. I expect to see temps around 220 going up moderate hills and 230 on long steep grades in second gear. So far, so good.

[hiyoag]

Following your thread with interest. I have a 1990 250 classic and when we brought it from Seattle to Vermont we went through the same overheating and gasket problem you have experienced with all of the same repairs. The 454 gets a workout in the mountains and it seems more cooling is needed. Recent posts have suggested airflow around the engine as a culprit and there are apparently vents in the wheel wells beside the block that can be enlarged. Any material in front that traps heat or flaps on the top to reduce water intrusion into the box may need to be removed. I am going to try that when it warms up a bit. Just want you to know you are not alone. The 454 may be a little small for the 12000-18000 lbs we are trying to move on long grades at high altitude. Hi yo silver!

[windfallsp]

Fan clutch can certainly do it. We had to replace the fan clutch on our 1985 345 twice, because the first replacement failed within a few miles.

The second "new" fan clutch plus recoring the radiator and installing a transmission cooler made a real difference in our 454's operating temperature.

Good luck getting your issue resolved.

[Grosspoluter]

I suggest you look at my previous post.
I had a problem with a belt falling off, my engine overheating and losing oil pressure.
Before that happened I always thought my 345 Ran Way too hot also but I have learned that about 210° to 220° is about normal also the temperature sending unit that runs the temperature gage on the dashboard is located on the cylinder head, it is always hotter on the cylinder head then it is on the intake manifold where most temperature sending unit are. I have two temperature gauges. the one on the head and there's one on the intake manifold intake manifold one is always about 5 to 10° cooler than the one that's on the head.
I live in the Midwest. so in the wintertime I have to run antifreeze in the winter. But in the summertime I drain the anti-freeze. and start using water and a redline product called water wetter, it seemed to help the problem with the overheating a little bit .
That said I also have a few older cars like a 1967 Ford 77 Jeep CJ 7 I thought they ran hot, and I install aluminum radiator, the aluminum radiator did make a world of difference on the cars.
This has been a learning curve for me also I considered the fan clutch but people on this forum have said you can hear the fan clutch kick-in when it gets hot. I have found that is true and my fan clutch does kick in at about 220°
Another thing to look for is a fan shroud, a fan shroud makes a huge difference on my cars. My radiator (on my motorhome Airstream 345) had a fan shroud on it when I bought it.
Ignition timing could also affect temperature but if your engine is running OK I would leave that alone for now.
I have course will be following this thread for my own learning curve hopes on the information I gave you will help are used to worry on my motorhome got the 220° but I just don't anymore but 230 and 240 that worries me.

[Jim Arnold]

Newbie here. OK The Anaconda has been setting for awhile and we are getting ready to hit the road. Would like to clean it up a little (outside), suggestions are appreciated!!

[bobmiller1]

I to had terrible overheating issues with my 325LE, during the second phase of the overhaul I had the radiator recored with a 4 row new core with larger tubes. I also purchased a seven blade fan which replaced the original 5 blade. In addition to the new AC delco fan clutch I was able to locate a NIB/NOS Delco correct 192 degree high flow thermostat. After an extensive 12mile mountain road test both alone and towing our car on the dolly, 2 separate trips I now rarely go above 205. Regards, Bob

[Isuzusweet]

Originally Posted by Jim Arnold

Newbie here. OK The Anaconda has been setting for awhile and we are getting ready to hit the road. Would like to clean it up a little (outside), suggestions are appreciated!!

Cheers
Tony

[guskmg]

About 454's: Regular 5 year GM radiator boil out, flush, and antifreeze change , new thermostat and radiator cap, and careful check of viscous fan clutch are mandatory for trouble free operation. The first sign that it is time for the above preventative service is when you hear the fan start up on a flat Interstate in the early part of the day when it is still cool out. The 454 is designed to run in a narrow temperature range. When modifying the cooling system there is such a thing as to much speed at which the water volume flows through the system. What happens is the water goes too fast to have time to soak up the heat and dissipate it through the radiator. More is not necessarily better. I had a friend who completely rebuilt his 454 due to overheating only to discover when it was all done it still overheated. He needed a new radiator cap to hold in the pressure to keep it from boiling. When operating with low oil volume, the oil, which is the major method of carrying heat away from the internal parts of the engine, the cylinders can become scored due to friction thus causing blow by of combustion gasses that severely heat up the engine even to the point of shut down. Oil viscosity that is too thin for the ambient temperature will do the same thing. As in using 10W-30 oil instead of straight weight 30. My GM dealer had me use HD 15w-40 diesel oil in my hot Texas climate 454. Never any damage either. I hope your engine problems are not as severe as you suspect, but if they are, I would get a crate engine and start over in your really nice motorhome.
guskmg

[Koheleth]

Once had a '86 345 that overheated so badly you couldn't drive it 20 miles. Turned out to be oily road grime stopping up the outside of the radiators (ac and engine), in between the two radiators where you couldn't see it. When that was cleaned out it would run 160.
Neal

[Toddnazus]

Thank you to ALL the contributors to this post !!!! I am very encouraged that we WILL find a solution and our "Magic Bus" will be rolling down the road soon enough !

I'll be printing off all of these ideas and running them past my RV shop manager and brainstorm with him which of these alternatives he may have already checked and which ones we should prioritize going forward !!!

FYI - This is my first ever post/question on these forums and I cannot tell you how pleased I am to find so much advice/support from my fellow Airstream Motorhome enthusiasts ! I will certainly be following and contributing (where my limited knowledge allows) more in the future!

Once we get a solid solution, I will let you all (and others watching the thread) know what worked and what didn't !

THIS SITE ROCKS !!!!!

Todd

[bkahler]

I've got a question and a couple of comments. The question is are the sheet metal covers installed on each side of the engine? These sheet metal covers can be seen while looking in through the wheel wells and somewhat blocking your view of the exhaust manifolds. If these covers aren't in place you can expect to experience elevated temperatures.

My first comment is when I was working on Peanut last year the engine temp would continue to rise after the engine was started and would overheat even at an idle. I pulled the radiator, had it re-cored and now the engine temperature barely gets to the point where the thermostat opens no matter how long it idles. My take off of this is the stock radiator in new condition appears to handle the heat load quite well.

My other comment is all fan clutches are not created equal. There are a lot of junk ones on the market. I believe the correct fan clutch for your 345 is AC Delco 15-4949. Other forum members have mentioned they had problems with replacement fan clutches until they installed the Delco unit.

Ok, one last question Has your engine timing been verified to be correct? Incorrect ignition timing can greatly affect engine temps.

Brad