1985 345 Major Overheating issues

[bkahler]

Ok, got another question. Has anyone checked the transmission? The transmission cooling lines run up to the radiator and if the transmission is generating a lot of excess heat that will directly affect the cooling capability of the radiator. Especially if the transmissions been working hard like it does when climbing hills.

When you're checking engine temperatures with the laser temperature probe check the transmission while you're at it.

Brad

[tevake]

Here is a success story of getting engine running temps into the comfort zone.
My 345 tended to run at 205/210 and would get hotter (mid teens ) when working hard.
Not crazy hot, but hotter than long term engine health calls for. IMO.
Also the long run times of the fan clutch was really bugging me.

After replacing the fan clutch a couple of times, and still having to listen to it running WAY TOO MUCH, I decided to go thru the cooling system from front to back.
1 new air damn, to direct air flow into engine compartment.
2 recored radiator with hi pro core.
3 new A C Daleco fan clutch and water pump.
4 lower temp thermostat, new hoses
5 have electric fans in front of radiator for extra cooling when needed.
6 had TBI dialed in for better tuning.

All of these done at one time makes it hard to isolate which had most effect.
But the result is a much cooler running engine. Generally low 190s. That will cool down quickly after a long hard climb on a hot day, allowing the fan clutch to disengage after short effective run time.
And a much more comfortable driving experence.

Todd it seems like you have done a lot in the effort to get your coach running well and at correct temps.
I'm hoping the problem in keeping your engine temps down comes to light so you can enjoy using your rig soon.

Cheers Richard

[Keyair]

ALL of the above comments are valid and many of the owners have been through this before.
It is a known and common issue, so hopefully the engine is ok.

Not sure if I missed it, but here is another couple of points if someone didn't already mention them regarding air flow and cooling.

The following points are critical in our motorhomes for correct cooling of the motor and other components.
1/ The bulkhead drapes need to be in place between the engine bay firewall, and top of the radiator. This creates a pressurized area in front of the radiator and increases flow, by stopping air flowing over the top of the radiator.
2/ Assuming your plastic fan shroud is still there, check the removable lower section is too.. It improves the engine fans ability to pull air through the radiator at idle and lower speeds. Mine is missing too.
3/ The engine side panels should be in place. These are metal sheets visible under the wheel arch either side. Passenger side is a flat panel, and drivers side is more complex to clear Hydroboost system. If they are missing, it is said to cause loss of airflow and therefore cooling for the exhaust manifolds, and increases the chance of warping and cracking.

[Toddnazus]

Thanks All,

I've passed all this information to the mechanics and they are reviewing it all to see what's what with our Bus's current configuration.

You have all been so kind with your feedback, I hate to ask for more.. But... Is there anyone that can post photos of the engine side panels ?

I'm currently traveling for work and not able to view our bus to confirm they are in place or not. But thought if someone could take some pics, I can have the mechanics make a comparison.

Much appreciated.

Todd

[WayneG]

Originally Posted by Keyair

3/ The engine side panels should be in place. These are metal sheets visible under the wheel arch either side. Passenger side is a flat panel, and drivers side is more complex to clear Hydroboost system. If they are missing, it is said to cause loss of airflow and therefore cooling for the exhaust manifolds, and increases the chance of warping and cracking.

I am curious if someone has pictures of this? I do not think my 84 270 have these. The PO did do a engine swap, so I may be missing them?

For me, I try to not drive overloaded or on days when the temps are over 80F. I do my driving at sun up whenever I can.
On a warm day or doing hills, my fan clutch kicks in often, but only runs for a short while,when it runs the temp gauge goes down and the clutch releases. So far the worst I had was a heater hose valve blow. I need to have the radiator reworked, the cores are OK, but there is corrosion at the tubes in the end caps. My dash engine temp gauge shows 210-220 I also run other sensors that show a lower temps, but in different locations.

One suggestion if you are concerned about engine damage from overheating and/or oil loss. Have your engine oil (and tranny fluid) tested. It is a inexpensive way to see what may be in your future. I use Blackstone Labs and they can tell you a lot with a sample of your oil

[Keyair]

I know I have pics of my drivers side, I will try to post.

The Chevy Chassis service book has great info on cooling and other issues.
Every owner should have a copy saved for reference!
https://www.airstream.com/wp-content...3be6cf5637.pdf

Especially read page 7-19 about radiator cooling.

[chiefair]

This might help: http://truckroadservice.com/barth_at...2015983041.pdf

See my motor swap post for pictures of several people's inner fenders and a template that I used to build my right side.

[Boom Sounds]

Heavy duty fan clutch is a possible culprit and a cheap repair if you haven't don't it recently. They usually have a couple of speeds and when they get faulty, they sometimes only kick in at high temps.

I am assuming the flush was successful. My knock sensor goes straight into the block. If you have the same set up, undo it to see if coolant runs freely. If it doesn't, you may have a partial blockage. This can sometimes be sorted out (be careful) by wiggling a screwdriver there to try and break up the debris without damaging anything.


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[tevake]

Here is the right side on my 345. It's a rather cobbled together install. But seems to do the job.
I haven't gotten a pic of the left side that shows it clearly. I'll try with more light if you like.
But after seeing this one I would think any reservations about making one should be gone. 👍

Cheers Richard

[chiefair]

Here is my right side inner fender that I added after my motor replacement.

[WayneG]

None of that shielding on my 84. It does not look to hard to duplicate.

[Keyair]

To add to the discussion.

On the RH/Pass side, this is the piece that sticks out on the front end under restoration. The slot is the infeed for the Heater/AC unit.


This is the assembly as I took it out, with the broken ABS Heater/AC duct. I need to make a new one of sheet aluminum.



The panel that goes behind that against the exhaust and RH bank of the motor is a plate piece of sheet steel, probably 20 gauge. I will photograph and dimension it when I go out to my MH next.

This is the Drivers side.

[bkahler]

Originally Posted by Boom Sounds

...I am assuming the flush was successful. My knock sensor goes straight into the block. If you have the same set up, undo it to see if coolant runs freely. If it doesn't, you may have a partial blockage. This can sometimes be sorted out (be careful) by wiggling a screwdriver there to try and break up the debris without damaging anything.

Nick, just FYI the 345 in discussion is an 85 model so will most likely be a carbureted engine so no knock sensor.

Brad

[Toddnazus]

These pics help immensely!! Thank you !!! the shop has a metal fabrication guy so they should be able to create something like this !

Once Again I appreciate all the comments and feedback ! I've shared these posts with my Shop and once I get home, we'll be able to review what's in place and next steps.

Right now, we're replacing the Fan Clutch (AC DELCO), I am having a custom aluminum radiator made, and we'll be looking at these shrouds too !

Hopefully.... Some of us we'll be seeing each other rolling down the highways soon !

[Keyair]

No problemo!

My guess is that you have the passenger side shield with the HVAC duct in it.
The other piece on the passenger side is a flat sheet, so dead easy to replicate.
That Barth template for the other side should be good, just compare it to the pics to know.

[bkahler]

A while back I ran across this write up describing the correct cooling & splash shields used on the later P-30 chassis motorhomes. Lots of good info with templates on how to make your own.

Since my Argosy doesn't have any shields I'll use the templates as a guide to make some.

Brad

[Toddnazus]

Latest Update !

Thank You all SO much for the Pics of the shroud... They had a metal fab guy and he's built them based off of your pictures ! So I greatly appreciate your efforts !

Secondly, we replaced the old fan with a new AC DELCO fan clutch.

After that... it was still running hot.... about 230 on flat ground...

So next they ran it with the engine cover off and determined that the engine temp was actually at 209... (gauges read 230 again).

They next looked to see where the sensors were inserted in the engine block... apparently they were inserted in the back of the block next to the exhaust manifold...

Next they moved the sensors somewhere near the intake manifold, and it ran at 75 and never crossed 210....

We did NOT do the aluminum radiator at this point, we were trying some last efforts before spending the money on that.

So.... Once Again I ask my fellow Airstream Fanatics who know much more then I do.... Does this seem reasonable ? logical and make sense ?

Need a gut check please !

Thanks In Advance,

Todd

[Boom Sounds]

I assume you mean 175, not 75. It's conceivable, although I would expect it to run a little hotter (185-190) on the flat in A1 condition. It might be possible to confirm operating temps through the use of one of infrared non contact digital temp guages.


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[WayneG]

I have 3 sensors monitoring the coolant temperature.
1) The original in the block, drivers side between piston cylinders. That goes to the dash gauge which in non linear and does read higher than it should.
2) The sensor in the front of the intake manifold near the thermostat. It is not original, it came with my TBI kit for the ECM to know the engine temperature.
3) I have a thermocouple wire inserted into a bolt also near the thermostat. I use this one with a laptop to monitor various temperatures in the MH. I monitor and log exhaust, engine oil, transmission fluid and a few others. I also monitor and log the ECM data with the laptop.

The results are #2 & #3 read very close to each other (between 190 & 200 deg.) because they are in the same location.
#1 reads higher (210 to 230 degrees) first because the stock dash gauge is not calibrated and second because the bulk of the heat generated in the engine is in the piston cylinders less than a inch away from that sensor. The coolant temperature there will be higher as it is doing its work.

On a side note, I monitor the exhaust manifold temperature at the exhaust crossover bypass valve and under heavy load that goes up to 1100 degrees! That is why I am interested in trying out this shield. My 84 does not have a shield on either side.

Since I am towing a trailer with my Polaris Ranger at 2000 pounds, I am also considering removing the air conditioner heat exchanger from the front of the radiator to improve cooling. I dont use the engine AC anyway. Pulling that and the compressor will allow for weight for necessities like beer to cool off when I get to my destination!

[WayneG]

Originally Posted by WayneG

I have 3 sensors monitoring the coolant temperature.
1) The original in the block, drivers side between piston cylinders. That goes to the dash gauge which in non linear and does read higher than it should.
2) The sensor in the front of the intake manifold near the thermostat. It is not original, it came with my TBI kit for the ECM to know the engine temperature.
3) I have a thermocouple wire inserted into a bolt also near the thermostat. I use this one with a laptop to monitor various temperatures in the MH. I monitor and log exhaust, engine oil, transmission fluid and a few others. I also monitor and log the ECM data with the laptop.

The results are #2 & #3 read very close to each other (between 190 & 200 deg.) because they are in the same location.
#1 reads higher (210 to 230 degrees) first because the stock dash gauge is not calibrated and second because the bulk of the heat generated in the engine is in the piston cylinders less than a inch away from that sensor. The coolant temperature there will be higher as it is doing its work.

On a side note, I monitor the exhaust manifold temperature at the exhaust crossover bypass valve and under heavy load that goes up to 1100 degrees! That is why I am interested in trying out this shield. My 84 does not have a shield on either side.

Since I am towing a trailer with my Polaris Ranger at 2000 pounds, I am also considering removing the air conditioner heat exchanger from the front of the radiator to improve cooling. I dont use the engine AC anyway. Pulling that and the compressor will allow for weight for necessities like beer to cool off when I get to my destination!

I guess I cant edit my post after a delay so I am quoting it.
For sensor #1, I was thinking of either another engine or the oil sensor, I just went out (in the damn April Fools snow) to verify and it is actually in the head on the drivers side. That is still a hotter location than at the thermostat.