1982 Chrysler 105HP - overheat alarm

[devl]

I have a 105 Chrysler that the overheat alarm light came on last time out. I replaced the impeller and tested the thermostat and it appeared to be running great on the muffs and the light didn?t come back on. I took it out again and the light keeps coming on after a few minutes of running (idle or under throttle). The water looks to be circulating great and I have a strong flow out the back. Is it possible the temperature sensor is bad? I couldn't find a replacement for it or a way to test online anywhere.

I did flush the motor when I changed the impeller and like I said it seems to be flowing great but should I pull the head to check for any blockage? Any other ideas? How hot should the top of the head be if it is actually overheating? The first time the light came on I literally burned my hand when I touched it (yea stupid) but now I can lay my hand on it and its uncomfortable but doesn't burn.

Other than the light coming on the motor is running great and the plugs look fine. Any help would be greatly appreciated, I can take a video later if that will help anyone.

 

[devl]

Here's some pics of the current sensor and a location it looks like to add a sender. If anyone has any leads on where I can get a new sensor or sending unit please let me know.

 

[Nordin]

Well I am not so familier with the 105Hp but the head would have a temperature about 80-90 dgr centigrade (I am in Sweden ).
The sender looks like a factory made sender (Force) BUT the powerhead is black and looks like a Force powerhead. has it been change?

The hotest part of the powerhead is at the exhaustplate. If you splash some water at it it should not boil. If it does it is to hot.

The Chrysler 105 Hp had a pressure releef valve that should open when RPM up from idle.
Maybe your engine has one and it is stuck, but I am not sure because your head looks like a Force.

Hope jerryjerry, jiggz or Frank chime in, they have more experience then I.

 

[devl]

Thanks for your reply. As far as I know it is all Chrysler but I cant be certain, is there a way to check if its a Force head? know engines pretty well but not all the terminology of outboards so can you explain where the exhaust plate is? Also where would I find the relief valve? I dont see anything apparent on the engine.

 

[devl]

No Title

I pulled the side cover (again not sure the terminology) and found a bunch of sand/small rocks in the bottom port. Is this the culprit?

 

[Nordin]

That sidecover is the exhaustplate, and yes it can be a part of the culprit.
Try to flush the cooling system (picup tube, waterjackets and so on). You can run the engine without the thermostate and se if it runs cooler. It is not hurting the engine but it will run cooler and sometimes that is not so good.Then you can state if there is a problem with the T-state.
The relief valve suppose to be in that square waterjacket in the lower left of the block.

The things that pointing me to that it is a Force powerhead are the black colour, the senders mounting and the head.

Chrysler had the sender threaded in to the head, the head was flat (no casting ribbons for heatsinking at the head) Force had the ribbons and the sender was mounted with a "locking ring" (I am not 100% sure).

I suppose it is a 4 cylinder engine and Force made a 4 cylinder 125Hp from 1983 until 1989 and a 120Hp from 91-94. Maybe it is a 125Hp block mounted on the Chrysler leg or a 120Hp.
Is there a ID tag at it? And what does it says.

BUT as I said try to flush the hole system and go from there.

 

[Frank Acampora]

That is NOT a Chrysler 105. It is a Force engine mounted on a Chrysler mid leg and lower. Note the smaller exhaust chest with larger water passages and less bolts holding the cover. Chrysler never made this version. Probably a blown engine replaced. The engine block itself could be a 115, a 120, or a 125

On the plus side, not only is the engine block higher horsepower but that block was rated at the prop while the 105 was rated at the crankshaft.

 

[Nordin]

Thanks Frank, you make may suspicions come true. That is a Force powerhead.
Just one question. Did Force made a 115Hp?

 

[Frank Acampora]

I say 115 because I bought a block from an old, retiring dealer and he told me it was a 115. I didn't think Force ever made a 115 but he assured me that it was definitely that. I have never actually seen a Force 115 complete engine. Note that Wiseco does not list a Force 115 in their catalog.

 

[Nordin]

Thanks, yes when looking at ishopmarine.com or mecrusierpart.com they does not list a Force 115Hp either.