9 replies to this topic

[minijazz]

Hi Groovers
I have been f*rting around trying to cure an overheat on my 998 A+ unleaded.
I replaced EVERYTHING that came into contact with water/ antifreeze and did the two-part fairly serious de-crud of my engine and hosed out the head, radiator and heater matrix. Replaced pumps hoses , stats & all gaskets.
Did the head gasket twice as I thought I had got it wrong first time.
On my drive , on tick over it got hot-ish - drive it about 3 miles went straight into the Hot on the standard gauge.
SO- I was getting cheesed off with this, so I ran it on my drive at about 800 rpm tickkover for about 1 hour with the RAD cap off and a thermometer stuck in the rad top hole- sometimes it touched the gills, sometimes I just held it.
WITHout the rad cap off , it got to a maximum of 80 degrees C on a chemical thermometer. It sounded fine.
Have I been a real twerp and only got a rad cap problem?
Is that overheating or is that about right for a 998?
Hoping its something simple like this as I have done everything else- the gauge does the electrical test thingy in the HBOL - should I replace the sender and cap - they are minispares ones at present if I need to replace whose kit should I get.?
If my engine is OK , thanks to all who helped me in a previous incarnation ( campfreddy 2)
cheers- all opinions please!!
colin

[Sprocket]

Have you fitted any tuning parts to the engine? Exhausts, filters and the like.

It could be running lean?

[minijazz]

Hi again Sprocket
No trick bits, but the timing is a bit suspect.
Could it be something as trivial as a rad cap ?
col

[ginigwunkle]

thermostat?

[Jammy]

My money is on the sender. I think your engine isn't overheating at all, but your guage is misleading you.

If the coolant heats to 80* and stays at the that it sounds like you have an 80* thermostat that is working fine.

[1984mini25]

Try changing the rad cap And if that doesn’t cure it try running it without the thermostat in, if it doesn’t overheat then it’s probably that that’s not opening/staying open.

[annodomini2]

My money is on the sender. I think your engine isn't overheating at all, but your guage is misleading you.

If the coolant heats to 80* and stays at the that it sounds like you have an 80* thermostat that is working fine.

I'm inclined to agree with this, if on your 3 mile drive where it went straight to red, when you stopped if it didn't blow the rad cap (steam everywhere) then I'd say it wasn't overheating, but giving false information.

[marsy]

hi sorry to drop in.
but i have similar problem, temp gauge stays at halfway when driving slowly, but when i accelerate the temperature gauge goes into the red right upto the top! which i was surprised with, as i thought this would of blown the water out somewhere! i replaced thermostat, i think like you guys have said it could be running lean?

[Jammy]

Or it could be the sender as I have said above...

For yours though it could be lean, you'll need a rolling road session to find out for sure, or try pulling out the choke (which will richen the mixture), see if that makes it better.

[marsy]

Or it could be the sender as I have said above...

For yours though it could be lean, you'll need a rolling road session to find out for sure, or try pulling out the choke (which will richen the mixture), see if that makes it better.

yeh ill give that a go! cheers