I have a 1996 vet. The engine temperature will exceed 260 degrees F when in idle for approximately five minutes. Installed new water pump, new thermostat, and new radiator. Engine mechanics at various shops can not solve the problem. Does anyone have any ideas or solutions to solve the problem. Thanks 9683w

 

260 degrees in 5 minutes!!!
Unless you have a serious air pocket in the system, doubtful as it existed before your repairs, I have never seen that much temp that quickly absent something seriously wrong where hot combustion gas was affecting the coolant either from a failed head gasket or a crack in a head or block.
Have you verified the accuracy of the gauge?
Does a temp gun indicate same when aimed at various spots of the system?
Mileage?

p.s
ask moderator to move to technical section, and you will get far more input.
Good luck and fill in some blanks, when and how did this begin?

Marty

 

Are you sure it is that hot? Analog gauges lie what does the digital gauge say? Do the fans come on? Did you pull the knocks when you flushed it?

Welcome to the forum.

 

If you don't have an Owners Manual here's a link to a '96. I believe the link will "stick". At page 2-70 and after the access to the DIGITAL DISPLAY for GAUGES is explained. Essentially just depress the GAUGES BUTTON on TRIP MONITOR/DIC until the CLUSTER LCD displays the data you're interested in. There's both OIL TEMP and COOL TEMP available, other information also.

https://my.chevrolet.com/content/dam...tte_owners.pdf

If the above link doesn't "stick" you can get to the OM from this link. You DO NOT need to establish account to access the OM

https://my.chevrolet.com/home

***Reading your post again you mention "mechanics can't solve" What have they done? What have they checked? Have you done any further checks yourself? You don't mention if this was a "before or after" so maybe if you've just done it and reused the ECT or the connector isn't connected or has internally failed very likely the PCM doesn't know to TURN ON THE FANS.

I'd do this maybe - COLD ENGINE - KEY ON what is displayed in the cluster LCD? Monitor that while the car is warming up and if it doesn't raise incrementally in comparison to the analog display then I'd assume "maybe" a bad ECT, bad connector. Is the ECT new? Do you get any "SES" in the DIC?

 

Are the fans coming on?

 

on my 96 starting from an empty system, it was fill, bleed off as much air as possible, start engine, watch temperature rise just like your engine, shut off, let cool, add coolant, bleed, restart, on mine I had to do this cycle four or five times before all the air got bled out, but once the air was gone, no problems.

 

I just get it hot while filling it with the right rear jacked up as I fill it and let it bubble out. Then have someone slightly rev it as I top it off and put the cap on.

 

Head gaskets??

 

If it is really getting that hot. I would borrow a pressure tester from a parts store and see if it is going into a cylinder.

 

I have a 1995 had same issue, Cooling fan would not turn on. Car sat at dealer for 7 weeks for the PCM to be sent out, repaired and returned. Now car runs great.

 

Looks like a one hump chump.

 

Until he posts the temp reading from the "Digital" gauge, nobody can say for sure if the car is overheating or not.

It if VERY COMMON for that analog gauge needle to get up close to the 260 reading.
It it not a linear gauge, and isn't very accurate at that.

Do as WVZR-1 mentions and get the owners manual, so you will know how to use the digital gauges.

 

X2 Check If your fans are working