Hot start smoking - Specific Circumstances

[lynns hubby]

Originally Posted by StrongSpearWorks

Interesting... I think the previous owner chucked some k-seal in to try and hide the weeping heater core (another fun job down the line) so perhaps those smaller hoses are being restricted by that gunk.

Full flush coming soon I think.

Good call LS. I had a leak develop in the heater core (steam from the vents when trying to demist) whilst on holiday several years back in our 94 wentworth. To get me out of trouble at the time I pulled into the nearest garage and bought a bottle of the dreaded "K" Seal. It worked and as I had no further issues I left it. Year later and I drained, flushed and replaced the coolant as part of a pre winter service. No issues there, however a couple of years again and for whatever reason I needed to remove the cooling feed pipe to the turbo. It was blocked solid. Had to blow through with compressed air. Interestingly, I never had any issues to suggest there was a problem. Eventually had to change out the heater matrix and as we all know, that's another story.

[StrongSpearWorks]

Originally Posted by 360beast

Every time I take an intercooler off a 940 there is loads of oil inside of it, chances are yours needs the intercooler cleaning out for a start and see if that improves matters. If there is oil in the intercooler (I bet there is) then oil is getting past the turbo seals.

I had the intercooler side off to check for end float and it was clean as a whistle - admittedly, I wasn't looking very hard, but I was surprised to see nice shiny metal rather than oily sludge.

What's confusing me is how it's not instant... you can almost time it.
2 mins after setting off... it's a smoke screen, then it clears and is fine for the rest of the journey.

[Laird Scooby]

Originally Posted by StrongSpearWorks

I had the intercooler side off to check for end float and it was clean as a whistle - admittedly, I wasn't looking very hard, but I was surprised to see nice shiny metal rather than oily sludge.

What's confusing me is how it's not instant... you can almost time it.
2 mins after setting off... it's a smoke screen, then it clears and is fine for the rest of the journey.

Check the lowest hose on the intercooler.

[StrongSpearWorks]

Originally Posted by Laird Scooby

Check the lowest hose on the intercooler.

I shall do that.

[StrongSpearWorks]

... after reading another post I opened the expansion tank when the engine was hot and running... bubbles. Not many, but maybe that’s also where some coolant is going. I mean, it’s a tiny amount (what ever the amount is between max and half way towards min) over the 300 miles I’ve driven since owning it. I thought it was all seeping out the control valve into the carpets... mystery machine.

[Laird Scooby]

Originally Posted by StrongSpearWorks

... after reading another post I opened the expansion tank when the engine was hot and running... bubbles. Not many, but maybe that’s also where some coolant is going. I mean, it’s a tiny amount (what ever the amount is between max and half way towards min) over the 300 miles I’ve driven since owning it. I thought it was all seeping out the control valve into the carpets... mystery machine.

That tells me a few things - first you need a new expansion tank cap. Second, your thermostat is probably lazy/knackered and third, you probably don't have a leak at all.

[StrongSpearWorks]

Originally Posted by Laird Scooby

That tells me a few things - first you need a new expansion tank cap. Second, your thermostat is probably lazy/knackered and third, you probably don't have a leak at all.

While I’ve got it off the ground tomorrow to change the turbo drain line and oring I plan to drain flush and fashion a new heater control valve and replace the thermostat. It does get up to temperature very quickly... but holds steady halfway on the dial regardless of the temp outside or how hard it’s being driven. No harm in swapping it out for a new one.

[StrongSpearWorks]

Well I didn't get as far as the oil return today... late start meant I didn't have the whole day to myself... maybe tomorrow, but I did have the intake side off, and took some pictures.

There's some oil in there after a long run, but not much to write home about.
However... the intercooler is definitley full of oil, as the pipe from the IC to throttle had a stream of wet oil in it.




Also discovered that the return cooling line from the water jacet had a kink in it, maybe not blocking it entirely but certianly restricting the flow.

I also noticed that the wiring from the O2 sensor was laying on the exhast pipe and was nice and charred, so I unplugged it and re-routed it round the back of the brake reservoir... must have disturbed or broken a toasted wire as now the Lambda light is on the dash permanantly.


It's like hearding cats with this thing..

Hmmm. Images aren't appearing. Link to google album: https://photos.app.goo.gl/saq3YU4ctpdo4bA38

[Laird Scooby]

Once you've repaired the Lambda sensor wiring, pull fuse #1 for 30 seconds to clear the fault code and the EML. Lucky it wasn't a short to earth on the +12V heater feed on the sensor wiring or you'd have an FTP - Failure To Proceed!

[StrongSpearWorks]

Originally Posted by Laird Scooby

Once you've repaired the Lambda sensor wiring, pull fuse #1 for 30 seconds to clear the fault code and the EML. Lucky it wasn't a short to earth on the +12V heater feed on the sensor wiring or you'd have an FTP - Failure To Proceed!

I'll be up early cutting open the cable jacket and splicing in some new wire... FTP - no start?

Edit. Two wires go to a connector, a third black wire goes to a push-plug with a green cable. Is that the 12v supply?