Hi,

Can anyone tell me what the pressure in a TD5 cooling system should be? It seems on my 1999 90 that the hoses are still hard even 3 hours after having driven for 45mins on the M6. The coolant level is at the bottom of the filler jar, but returns to normal if I let the pressure out slowly via the filler cap. Is this normal? I am losing a little coolant through the pipe joint at the thermostat.

Thanks,

Chris

 

I am guessing your pressure should be at about 15#s , same as a gas engine.
Where does your coolant level sit when cold? I would suggest you raise it so that when the engine is hot your level is an inch or tow from the bottom of the bottle.
As for the hoses staying hard, sounds normal for your hose to hold pressure longer, it is a diesel and a big block to cool. Should get that coolant leak fix sooner then later.
Mike

 

Thanks Mike,

It was more a question of whether the head gasket might be leaking and allowing gas (air or exhaust) to pressurise the cooling system. Having said that, no water in the oil, no oil in the water etc etc. I do have a slightly odd trait - when I'm at 70mph and I accelerate hard to overtake, the engine sometimes faulters. I was wondering if the two were connected.

Chris

 

I don't believe the two have anything to do with one another. I would suggest you have a shop do a pressure test on your coolant system, make sure it is not running to high.
As for the hesitation, cna't help you there.
Mike

 

Thanks for that! Taking it in on Wednesday to have the engine looked at.

Chris