Coolant pressure probs

[gpz550]

Hi, this has probably been covered before, but I did not see in the lists.
My 1989 350 has a coolant problem, seems to be very high pressure causing expansion cap to release pressure and thus water out of system
Someone mentioned to me that if head gasket was gone this may also do this, but have checked compression on all cyls and found all to be about 160 - 165 psi which seems fine. I've changed the cap and thermostat recently for an over fueling problem recently so they should be ok. There seems to be far too many hoses to trap air in and the heater givees out hot air (no cold input)
Any other things I could try ?

Cheers
Any other sugeestion out there,

[2 Sheds]

Generally Engines will find their own level, leaving enough air in the expansion tank, have you tryed leaving it to see if it stops, sometimes the expansion tank needs only 1/4 water, indicating that they are too small.

[shpub]

Still might be a head gasket problem as the compression test is not foolproof. need to see if there is any hydrocarbon contamination in the water to conclusively prove the gaket is OK.

steve

[gpz550]

I have now let the water settle to about 1/2 inch of bottom, no more expelling, but would this not then let air in the system as it circulates. Seems to be now running just below 90 at motorway speeds and then creeps yp to the solid white line in traffic. Does this sound about right. Steve how do you test for hydrocarbons in the water ?

[shpub]

You go to a dealer who has a chemical test kit.

I think Frosts sell them as well IIRC.

[Schazzar]

My car runs the same temps. Sits midway on the motorway then creeps up the the 90 with the fans cutting in just below the red. Hasn't overheated and proves to be conistant on every run.

[danny hoffman]

It sounds like the car is running way to hot. My 350 sticks at 80 degrees ever since I upgraded to a 3 row rad. Even in the boiling heat on Monday stuck in a long traffic jam - it didn't reach 90

Danny

[Schazzar]

quote:
It sounds like the car is running way to hot. My 350 sticks at 80 degrees ever since I upgraded to a 3 row rad. Even in the boiling heat on Monday stuck in a long traffic jam - it didn't reach 90

Danny

Hi Dan, thanks for your comments. I'm interested in your rad upgrade though. What is a 3 row rad exactly, is it the same as a 3 core etc?

Living in London I'm seriously thinking about fitting a 2 stage overide kit, even though it hasn't overheated as such but as the engine pinks when it gets hot my suspicions lead me to the conclusion the heat doesn't make matters any easier.

[tvr350i]

Well, Steve may have a different view on this but mine went over 100C before fan started and all i did was changing to a 74C stat and replaced the ordninary 50/50 Swedish mixture with fresh water, only 2 litres of glycole and a bottle of Water Vetter. Now it NEVER gets over 80-82C and the fan starts around 80C (??). Maybee it´s some "thermodynamic" thing...? Still, i'm happy with it ! Think i´ll try some 80C stat to get it warm i bit faster.

bengt

[danny hoffman]

Sorry - I meant to say 3 row core. I had mine converted for about £150 inc VAT by my local Serc Marston. A very worthwhile upgrade IMHO

Danny

[montegogt]

So you were worried about your temperature? Well, haveing sold my S.2, I purchased a nice 350i. Collected it from Milton Keynes last Saturday in the 90C temperature and noted that it remainded just above the blue bit in the gauge. Sunday. Took new Wedgie for outing with girlfriend, who always cried when I took her in the S.2. Girlfriend quite happy in 350i, and we cruised to watch the Moth Club Rally at Woburn Abbey. Had to queue to get in...temperature started to rise...peaked at 100C, no fan noise, but we moved off again in a line of traffic...temperature dropped to 80...then we had to stop again...then had to negotiate rough track at sensibly low speed...temperature at 100 again...then...steam...lots of steam...clouds of steam...
Needless to say there was still no fan noise! After letting it cool down, it only took a litre of water to top it up. Once home, I checked the fuses and hot wired the fan to make sure that was OK. I'm just surprised that over its 15 year life, none of the owners had fitted a fan overide switch. Wire, connectors and switch are now ready for fitment. Pity I pulled my back checking the systems out yesterday! Is there anyone who can help an elderly white haired gent of of his 350i?

Lee

[bluewedge]

Do yourselves a favour - short out the wire to the fan/s and bypass the otter switch (Waste of time). Keep the fan running constantly even from start up. Did this 2 weeks ago on my car and it has kept the car at a constant 80c, cured my pinking and now pulls brilliantly in any gear. Doesn't get anywhere as hot even if stuck in traffic.

The Rover V8 has always had cooling problems and before TVR started using them - they always had constant cooling from a fan when Rover started using the V8 in their cars. Takes the stress out running a great car.