MK5, Sometimes overrevs, Smokes, Random problem

[therigsmith]

Hi

I have a Portuguese Mk5 transit. 1998 non turbo. Same engine my English Van had of this age.

Sometimes, Usually from the first 10 mins of starting the engine. Its like my accelerator gets stuck (Possibly stuck although today I am sure it started from low revs not full peddle). It revs loads and loads like full peddle and chucks loads of smoke out (Not sure if its exhaust or clutch or both).

While its revs loads its impossible to stop. Even once turning the key off did not stop the engine. I found the only way is to hit the accelerator to the floor which seems to clear the problem. I worry if this dont work I will blowup my engine unable to switch it off.

I replaced a worn nylon washer on the link from butterfly accelerator arm, this seems to work for some time but it happened again today. today it was like I as not foot down, the van started to get really ruff and then just started to rev to hell.

What happens is its revs randomly climbs really high. At first I though it was due to accelerator getting stuck when foot down but today I think it started without my foot down.

It usually seems to happen going downhill. I am noticing this pattern.

Its really hard to work out the problem. when it happens it makes you panic a little rather than look for the problem. apart from starting engine cold its not always happening so its hard to find out why.

Any advise or things to check I will be really great full

[mike En]

If it does happen and you cant turn it off, put your foot on the brake, handbrake on, stick it in a high gear ( 3rd-5th) and stall it !
Do it as quickly as you can aswell to save damage being done.
Don't know if it could be worn seals letting some oil through in to the combustion chambers ? Or something to do with the fuel pump maybe letting to much fuel in ?
My connect tdci smashed itself to pieces when the turbo seals went last year, revved its nuts off for about 20 seconds while i tried to pull over and stall it.

[Altransit]

There's a 10mm headed bolt, under the rocker cover, which comes undone and lets engine oil into the combustion chambers. Check this first

[BLUDGEONER]

There's a 10mm headed bolt, under the rocker cover, which comes undone and lets engine oil into the combustion chambers. Check this first

Definitely check this first!! I just had very similar symptoms, and this bolt was the problem. Thanks to the advice I got on this forum, it was a very easy fix and saved me junking a perfectly good engine!

[therigsmith]

You guys saved my life again.

Thank you so much. It was the lose bolt.

Took me maybe 1 hour cleaning the gunk, + 1 hour doing the job (I am not a pro mechanic). proper messy thick burnt oil under the rockers cover.