Heater matrix replaced, so is the thermostat the issue now?

[markuskj007 0]

Hello there

 

The back story is that over Christmas, in -12 temp the heater matrix went bang. Managed to pull over immediately so hoped for no damage.

 

Had it garage fixed as I was away from home but the guys were pulling in a favour as it was the holidays so did nt have a chance to do a full test.

 

I drove it down from Aberdeen to Glasgow and although it started to warm up to about 84 on the digital reading the temp dial barely moved, then it dropped continually 2 degrees every 10 miles or so. I pulled in and found this excellent article "The definitive VR6 cooling guide - viewtopic.php?f=1&t=68720" which suggested a thermostat issue. After nursing the car home with frequent stops I read up more on the forum today and see that getting at the thermo is no easy job.

 

Before I attack this I wanted to check that this looks like the culprit?

 

What do you guys think?

[davidwort 0]

if the stat is stuck open it will cool the engine far too much as soon as you drive away, in fact in these temps probably at idle too, so it sounds like that.

[markuskj007 0]

if the stat is stuck open it will cool the engine far too much as soon as you drive away, in fact in these temps probably at idle too, so it sounds like that.

 

Thanks Dave. What would happen if untreated? Also, is there any 'safe' way to get this to a garage without a trailer?

[davidwort 0]

as long as the coolant has enough anti-freeze in it to stop it freezing solid (in which case left standing is your problem, not running!) and the coolant level is OK, i.e. not losing any, then if the engine is running OK at idle and the hoses all start to get warm after a few minutes, so you know the water pump(s) are OK, then you could simply put a piece of cardboard in front of the radiator so the airflow doesn't cool the water in the rad too much when you are driving.

You may still find the car runs a little too cool but it should get enough warmth in it to drive fine.

I had this on my old mk1 years ago, stat stuck on a long journey on the A14 one night, PITA to have to keep pulling over to let the engine get a bit of heat into it, then it driving OK for 2 minutes :mad2: :lol:

[markuskj007 0]

as long as the coolant has enough anti-freeze in it to stop it freezing solid (in which case left standing is your problem, not running!) and the coolant level is OK, i.e. not losing any, then if the engine is running OK at idle and the hoses all start to get warm after a few minutes, so you know the water pump(s) are OK, then you could simply put a piece of cardboard in front of the radiator so the airflow doesn't cool the water in the rad too much when you are driving.

You may still find the car runs a little too cool but it should get enough warmth in it to drive fine.

I had this on my old mk1 years ago, stat stuck on a long journey on the A14 one night, PITA to have to keep pulling over to let the engine get a bit of heat into it, then it driving OK for 2 minutes :mad2: :lol:

 

Thanks David.

 

I plan to get it in to the garage ASAP. The levels were topped up at the garage and heavily doped with anti-freeze.

 

Excuse the thickness but is the issue with heat that the engine does not get up to operating temp, is there anyhting else that becomes an issue

[davidwort 0]

it'll just use a lot of fuel as it's going to think it's at the start of the warm up cycle temp-wise, probably wouldn't do the cat/lambda sensor a lot of good if you drove it like that for ever, but I can't see it will be a problem for a short period.

[markuskj007 0]

Thanks for the advice. It was the thermostat which was in a poor state - bugger to get at eh!

 

Car now beautifully warm even at -6 on the way home.