series 3 petrol getting hot (I think)

[morg]

Hi All,

2.25l petrol, new radiator, new hoses, new 80 something degree thermostat.

I have recently replaced pistons, rings and had the head done up and now the temp gauge sits just on the red when it used to sit about three quarters up the white. After a short run ( about 3 kms) the needle is alread in the red and the radiator is quite hot. I can still hold my hands on the top of the radiator for a few seconds and it doesnt sound like it is boiling or hissing.

have I prehaps got a faulty temp guage or reattached it wrong when we reassembled the engine? I cant actually remember touching the temp guage but guess if i had the head off etc that it probably was pulled out at some stage in the process.

Any ideas?

Thanks in advance,

Morg

[Blknight.aus]

with it cold remove the radiator cap, make sure the radiators full and stick a thermometer in the coolant, crank it up and let it run.

watch the coolant flow, if the radiators blocking that'll acount for it.

[CapeLandy]

I installed a VDO gauge and much more peace of mind. The original gauge is in the red but VDO is at 80.
Sometimes on a long slow uphill on a hot day mine starts to boil even with an extra electric fan - just have to stop and wait:cool:

[JDNSW]

Possible problem is an earthing fault - either engine/chassis, chassis/firewall or voltage stabiliser to firewall, or the temperature sender could have been damaged while the head was off. But as indicated, the first thing to do is to find if it really is overheating.

John

[morg]

Can I get a "VDO" from auto barn or super cheap?

I had a look without the cap as described below and everything seemed ok.
Then (mayby the wrong thing to do but anyway) I took the thermostat out and let it warm up slowly before taking it for a 15min drive. The gauge came upto just over halfway and that was it.

The thermostat opened in a saucepan of water at about 85 degrees so I guess it was working.

I dunno ;)

[Lotz-A-Landies]

If an engine has overheated significantly, you sometimes have to replace the OEM temp sender unit. Worth a try before you drill holes to fit a VDO replacement sender and guage.

I would replace the sender and run the engine with a temp probe in the radiator as Blknight has been mentioned above. Then you can decide if you still need the VDO unit.