87 4.3 temp fluctuation.

[moondrifter]

This is for a friend who just had his water pump assy changed but temp raises to 200 when at idle.
There were no pieces broke off the old impeller.
The thermostat was changed last year.
I found the thermostat housing online but looks like it is not made anymore. It has check balls inside. The new superceded part has these check balls outside.
I looked for past post on the manuel for 1987 4.3 Alpha but cound'nt find it.
Any ideas ?
Got a link to the manuel?
Thank You.
Moondrifter

 

[chiefalen]

Copied from another website i posted this.

[FONT=Verdana, Arial, Helvetica][FONT=Verdana, Arial, Helvetica]First you have to know if you have good water coming into the boat.

Submerge the drive, and then wherever the raw water hose goes to say the t-stat or a heat exchanger remove it from that spot.

Then start the motor hold the hose straight up if you have 8-12 inchs of good water you good to that point.

You need do this for only 3-5 seconds quick shut off the motor.

Now say you got good water to the t-stat the you have to open the t-stat cover.

Me i would remove and replace or remove and leave empty the housing and close it up.

Run the boat if it over heats again then you know with no t-stat it's for sure a blockage down stream.

Then i'm betting the riser / elbow is clogged.

Now be aware a flapper / shutter could be blocking the exhaust. So if you pull the risers then look for them not there then you got to fish them out.

My own opinion i hate flappers and remove them. They cause alot of trouble and are just not worth it.

Say you don't have good water to the t-stat or exchanger then you know the problem is ether the hose is kinked inside the transom at the thru fitting to the drive.

Or the fitting on the outside of the transom that feeds the raw water hose is clogged, or the impeller went, or the water pump housing went.

Volvo says remove them if you have them and do not replace them if they go.

Good luck !
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