Unusual Coolant Issue

[Don in VT]

Hi

An update at 1:00 PM Vermont time,

I needed to use the ZR for a 1 mile trip to the store. When I backed out of the garage I left the car running while I went in the house to get something to take with me. When I go in the car I noticed that the heater was beginning to blow warm air. When I got to the store the temp gauges had just moved off low peg. When I got back in to go home the water gauge had moved up a bit the oil temp was still at the low peg. I decided to take it down the road a ways to check this new condition out and I found that the water and oil temp was moving up VERY slowly. Much slower then ever before. I drove about 10 miles and checked, by feel, the temp of both water manifolds and the cam covers and they seemed to be reasonable and not too hot. The water temp gauge worked its way up to 140 and the oil was about 110. On the water temp I usually run about 180.

Sorry for the long winded story but I now am convinced that I have a flakey thermostat and it is now stuck open. It may not be the whole story but I am going to change it out anyway.

More later

Don

[WARP TEN]

Originally Posted by Don in VT

Hi

An update at 1:00 PM Vermont time,

I needed to use the ZR for a 1 mile trip to the store. When I backed out of the garage I left the car running while I went in the house to get something to take with me. When I go in the car I noticed that the heater was beginning to blow warm air. When I got to the store the temp gauges had just moved off low peg. When I got back in to go home the water gauge had moved up a bit the oil temp was still at the low peg. I decided to take it down the road a ways to check this new condition out and I found that the water and oil temp was moving up VERY slowly. Much slower then ever before. I drove about 10 miles and checked, by feel, the temp of both water manifolds and the cam covers and they seemed to be reasonable and not too hot. The water temp gauge worked its way up to 140 and the oil was about 110. On the water temp I usually run about 180.

Sorry for the long winded story but I now am convinced that I have a flakey thermostat and it is now stuck open. It may not be the whole story but I am going to change it out anyway.

More later

Don

In normal driving it takes me about 5-8 minutes to get oil temp up to 160. --Bob

[Don in VT]

Hi Warp 10,

Thanks for the input

Yes, my oil temp rises much slower then the coolant but my oil temp only get to about 130 tops. For the water temp I use the HVAC diagnostics to get the actual water temp. Works great and it is somewhat accurate as well.

Cheers,

Don

[Schrade]

If there is no flow the engine is air locked ...

Air 'locked'?

Does this mean that trapped air won't push through, and get 'burped' in a few drive cycles???

[Don in VT]

Hi All, Thanks for all the replies.

Replaced the thermostat. Bought the stat from Jerry's Gaskets so I know it is the correct one. Checked air bleeds, all clear. Thanks Mark H.
Runs great.

Installing 2 new wheel bearings later this week then the ZR is off to its winter slumber. Can't wait till spring.

Cheers,

Don