interesting issues with a 940 turbo

[lixah]

Originally Posted by 360beast

If the downpipe was loose air could get in and give the lambda a false reading which could then overfuel it and cause running issues. The lambda probably needs changing as it has had a knock on surprised it hasn't brought the code on as they're a sensitive piece of equipment.

yes, i noticed a big dent when i had it off during inspection. fingers crossed, i honestly just dont want to take it off again, so far no warning light on.

but it was incredibly loose, just barely holding on

[Laird Scooby]

See how it goes Matt, glad you've got it sorted anyway and what Luke said about the loose exhaust pulling air in is spot on.

The buzzing from the NSR wheel is probably the in-tank pump so at least you know it'w working!

[griston64]

Originally Posted by Laird Scooby

See how it goes Matt, glad you've got it sorted anyway and what Luke said about the loose exhaust pulling air in is spot on.

The buzzing from the NSR wheel is probably the in-tank pump so at least you know it'w working!

When the buzzing goes up to Chinook helicopter sound it's time to change it

[lixah]

Originally Posted by griston64

When the buzzing goes up to Chinook helicopter sound it's time to change it

i more just worry, that that's what caused me to stop on the way home , lol

[Dirty Rooster]

Originally Posted by lixah

... it was about an hour into my journey home that i started to have a real problem. drive started to cut out, it felt like fuel cutting out, like a fuel pump failure or something. i quickly took the next exit off, and managed to get into a quiet spot in an emergency lane.

for the next 30 min i couldnt get much power, however the engine never cut out, but would almost die when trying to accelerate (IN FIRST)
another weird thing, because of where i was stopped, trying to merge back onto the roundabout/get the lane that i needed, combined with not being able to accelerate, i had to reverse a good few times, what has me puzzled, is that it never seemed to have an issue in reverse, and then randomly i was also able to pull away again, in first. and while the rattle/vibration noise didnt go away (i was very very careful to try and keep to just gently rolling behind faster traffic) i didnt have any other issues on the way home.

The two commonest faults that might (-ish) cause something like this,
in my experience with eightish years of this car
are the Crank Position Sensor (down the back of the engine) CPS
and the Fuel Pump Relay (behind the cigarette lighter tray) FPR

It's kind of a good idea to replace them with new if you can get them cheap or have them already.

A failing CPS always gives you a rev-needle fluctuation/fail when it goes wrong which can be totally intermittent.

A failing FPR gives "oh no I've run out of petrol" feelings and later it's fine as it cools down.

Might be helpful.

Exhast & CAT look normal as has been said.

[lixah]

Originally Posted by Dirty Rooster

The two commonest faults that might (-ish) cause something like this,
in my experience with eightish years of this car
are the Crank Position Sensor (down the back of the engine) CPS
and the Fuel Pump Relay (behind the cigarette lighter tray) FPR

It's kind of a good idea to replace them with new if you can get them cheap or have them already.

A failing CPS always gives you a rev-needle fluctuation/fail when it goes wrong which can be totally intermittent.

A failing FPR gives "oh no I've run out of petrol" feelings and later it's fine as it cools down.

Might be helpful.

Exhast & CAT look normal as has been said.

interesting, this car has just recently had a timing belt (iirc <400 miles prior to me getting the car)

thinking about it, it's very strange someone would have the timing belt done, then get rid of the car so soon, unless it had created this problem.

ALSO, if the same garage is responsible for the mess that was the downpipe/exhaust, then i wouldn't be surprised if they messed up the timing too.

can anyone say whether my issues could be due to an incorrectly set timing setup when the belt was done? and/or how can i check the timing setup myself?

regards, Matthew

[lixah]

so i got some spare time today.

i opened the top part of the timing cover, and ligned up the cam marking, the lower one looks to be one tooth off? am i correct in thinking this?

i have not done a cam belt before, so advise would be apprecaited.

regards, Matthew

[Laird Scooby]

You're correct Matt, it certainly looks that way! It's normal practice to line up the crankshaft pulley with TDC (the mark you've lined it up just past) and then check the camshaft pulley. Fairly sure if the crank pulley is one tooth out (always turn the crank pulley clockwise as viewed from the front) the cam pulley will in fact be out as well.

Also if the timing belt was allegedly changed before you got the car (i think you said something about it) then i'd lay bets the belt wasn't retensioned after 600 miles.

Best bet is to wind the crank pulley 2 full turns clockwise from where it is, stopping so the marks are lined up and then see how far the cam pulley is out.

Once you know that, then it should be easy enough to guide you through how to correct it.

[lixah]

Originally Posted by Laird Scooby

You're correct Matt, it certainly looks that way! It's normal practice to line up the crankshaft pulley with TDC (the mark you've lined it up just past) and then check the camshaft pulley. Fairly sure if the crank pulley is one tooth out (always turn the crank pulley clockwise as viewed from the front) the cam pulley will in fact be out as well.

Also if the timing belt was allegedly changed before you got the car (i think you said something about it) then i'd lay bets the belt wasn't retensioned after 600 miles.

Best bet is to wind the crank pulley 2 full turns clockwise from where it is, stopping so the marks are lined up and then see how far the cam pulley is out.

Once you know that, then it should be easy enough to guide you through how to correct it.

I will do that, and report back the results, some other things I found, that are note worthy.

people say (from my understanding , i may be wrong) but the crankshaft pulley is a two piece design with a rubber insert. and that old/worn pulleys can sometimes slip, meaning i would potentially have to have it completely apart to get an accurate view of the timing alignment. although, this car has only 100k miles on it! so i would be surprised if that would be my case.

Also, yes, the car has a sticker for a timing belt at <400 miles ago, (that's including the ~120 mile trip home, that I did) a very strange thing to do, right before scrapping your car!

-Matt

[Laird Scooby]

You may have something there Matt, perhaps the problem isn't just the cam timing is out although that could cause a lot of problems. Maybe the mechanic did it deliberately knowing it would still run but not be right then would make a silly-cheap offer to the owner to buy it. Then the owner decided to scrap it instead.

If the crank pulley has distorted, the only solution is to replace it, however you can determine if the piston is at TDC with a pencil in the spark plug hole - insert the pencil as you are approaching the TDC mark so it sits on top of the piston and observe it as you bring the crank pulley round. There will be a spot with no movement either side of it and that should be TDC - usually it is only a problem on high mileage cars though and 100k isn't high mileage really.