water temp variable readings

[redhotwheels]

Hi there,

Was wondering if anyone can help or shed light on this issue:

The water temprature reading is a bit erratic - sometimes it reads hot and sometimes 'normal' - if you stop the car, turn off...then fire up again the reading will change (the range of this is some 20 degrees).

So - the temprature gauge can't be relied upon...not good! We have a switch to manually kick in all the fans fitted by a PO ...so at least that gives some piece of mind.

I was wondering if this was a common(ish) problem or is experienced by others?

Looking at the wiring diagram in the service manual shows that there is a voltage stabiliser connected to the water temp gauge...could this be the issue?

Coolant levels are OK and the car is driven pretty regularly - so air lock shouldn't be an issue.

Any comments welcome.

Happy driving - Steve and Kay '88 Turbo HC

[lotusman]

As Einstein said, "Everything is relative." On my '89 non-SE there is no, "NORMAL" section on my temperature gauge. Here in Louisiana, if I stop at a light for 5-6 minutes my temp goes up to 97 degrees. Once I start moving again it drops to 84. When was the last time you flushed the coolant system? It once took me four flushings do get the coolant to flow clear.

So, what are the actual temperatures? Where do you live to get these temperatures? Do you have the Freescan set-up to tell exactly what these tempratures are? When does your fans come on? Should be 93 degrees.

Remember, you have basically an, "Engine in a box". There are ways to improve on the air flow in the engine bay. I cut out the other two openings in the pan and covered them with shop cloth. Worked great; did not even need to change out the red hose, though I may later for fun. I've owned the car 8 years.

It sounds like the PO had a problem he may not have told you about.

I had the coolant pump changed at 20,000 miles when the timing belt was changed. Is the life span of the coolant pump blades better than that of the chargecooler pump? Anyone?

Please let us know.

Lotusman
'89 non-SE

[redhotwheels]

Hi Lotusman,

Thanks for the reply....

No ECU - so no freescan on my 88 turbo HC.
Driving the car in the UK, so ambient temps are pretty low (still!). The fans are cutting in on the otter switch OK - I think the manual fan switch was just put there for peace of mind since this switch can fail with the expected rsults.

The problem is not the actual temprature of the coolant (I'm pretty sure since we have owned and driven the car regularly for the last 9 months)...but rather the innacuaracy and fluctuation of the reading from the gauge.

I was wondering if anyone had experienced bad earths or faulty stabiliser causing this before I start head scratching - auto electrics is not one of my strong points! LOL :-(

I take your point about flushing the cooling system and this could well be a job that we can do. Have you any tips for procedure? Are air locks a problem?

Thanks again Lotusman - happy driving.

Steve & Kay

[86turbo]

Just my two cents, but when you shut off a car and then turn it back on, isn't it normal for it to be a bit hotter (especially in hot weather) because while the engine is off no coolant is circulating through the engine? A difference of twenty degrees does seem quite extreme though, just giving you something to think about.
Dan

[lotusguy]

Hi,

There is a voltage stabilizer on the '88s. These do go south, but more commonly, the ground connection loosens or corrodes and this can make the gauges erratic.

But, that having been said, the problem manifests itself as having the gauge go all the way to the right or extreme hot along with the fuel gauge doing the same thing as they are both regulated by this device.

Believe it or not, giving the right side of the binnacle a good rap with the palm of your hand will usually take care of the problem if it is ground related, albeit temporarily. If the gauges return to normal, this indicates that the stabilizer should be removed and the contacts cleaned and reinstalled tightly.

However, your problem does not display the classic symptoms, so I doubt this is the cause.

I suspect that this is just a normal overheat condition due to heat saturation on shut-off. Another thing to check for is debris which has worked it's way into the radiator and is reducing the airflow. This requires cleaning the radiators from the backside with a pressure hose (air, preferably water) to flush the dirt, leaf matter etc. out from the matrix, restoring the proper airflow.

All Esprits are prone to this and should really be cleaned annually, more as needed, to maximize airflow through the radiator. Hope this helps. Happy Motoring! ...Jim'85TE

>> Edited by lotusguy on Wednesday 14th April 14:21