Had a “new” Jasper engine installed in Nov 2023. Earlier this year, engine ran hot and had to have new thermostat and housing installed as housing was cracked.
Drove vehicle about 20 miles, it sat for 15 minutes, drove it 2 miles and it sat for 15 minutes, drove it less than 1.5 miles when noticed no air conditioning. Looked down and temperature gauge had pegged out past High. Stopped immediately and had truck towed to mechanic that did the above work.
At first it was thought head gasket issue. Gauge on radiator showed high PSI (see pic from mechanic while diagnosing).
Heat tabs have been checked, cylinder pressure checks, and block test. Supposed all ok.
now being told this:
“I found some kind of fine plastic bead like material in the cooling system. But I’ve flushed it 3x. Replaced thermo again and drove it 20 miles no issue.

I can’t account for the pressure reading though. All the cylinder leakage tests indicated normal
I’ll call the engineer back Monday and discuss it”

Anyone have any thoughts? We’ve not added any fluids to the coolant system.

 

What year? Original radiator and heater core? How many miles?

Was the driving in that trip record all local?

The mechanic said he drove it 20 miles after 3 flush-outs? Did he pronounce it clean? Did he restore properly mixed coolant?

Is your pressure gauge accurate?

 

Yes, our driving was local. The pressure gauge pictured is from the mechanic. He still has our truck. He can’t explain why the pressure was high when he first checked it. Not sure if it still is. He is the only one that has put any fluids in it on 2 different occasions (Jasper engine install & thermostat & housing install). What do I need to ask or know? Much thanks!!!

 

What has the passage of time done to this truck besides destroying its engine?
Was this truck neglected or abused by a previous owner?
By 'cylinder pressure checks', you mean a compression check was done on all 6 cylinders? No exhaust smell in the coolant?
Has the mechanic driven it another 20 miles?
Was the fan controller unit working?
The mechanic you mention is the party who installed the Jasper, yes?

 

The truck was never neglected or abused. In Nov 2023. We bought the truck used but have had it over a decade. It had ~105,000 original miles when we replaced the engine in Nov 2023. It had a valve stem crack and fall on a valve.
The “new” Jasper engine has less than 10,000 miles. It is not our primary vehicle. We use it as a work truck. We are retired and only do small electrical jobs.
The Jasper has been serviced and maintained as instructed.
The only reason we noticed the truck running so hot was that we lost air conditioning and fan was blowing warm air.
The mechanic is the one that drove it 20 miles. He still has the truck.

 

Could it be that the cooling system wasn't bleed properly after the first repair? Like heater on hot and wait until the thermostat opens?

 

The first repair after the engine was done a few months ago. I think something would have shown up before now.

 

Of course. Sorry, I thought it was right after the repair.... must have misread...