TD5 Down on Power After Head Gasket Repair

Re the last two posts, this thread has been dead since March this year and the author hasn't been online since receiving very good advice at that time. I suppose we'll never know what happened.

Hi that is sad ,mine is still the same wishes that someone could just reply what the problem was i know that iet is not just this two independents...

I don't know enough about rhese vehicles yet but am learning lots from this forum.

Have you done all the checks suggested in the thread, including the timing which the o p hadn't seemingly done?

Sorry I never updated everyone on this thread.

Timing was fine as far I could see (I got the TD5 timing tool). Checking anything else is pretty much beyond my limited abilities - bearing in mind I'd already had 3 independent specialists try to diagnose it (and all failed at a combined cost of around £600 in diagnostics and unneccesarily replacement bits) I've accepted it's unlikely to be anything an amateur like me could identify or fix.

Never did get to the bottom of it and the car having stood for over a year the XYZ switch on the gearbox is now throwing it into limp as you pass through 'R'. Couple this with the already very low power, getting past 5 - 10mph is almost impossible and not safe to use on the road even to get it to a local garage, plus the MOT is now out so it's being scrapped.

I must be a glutton for punishment as I'm now looking for a 4.6 P38 to replace it.

Most obvious checks would be
* to check that you're getting 4 bar of fuel pressure at the FPR (left side rear of head as you look at the engine), if you don't then the pump isn't working properly - they can 'part fail'.
* get some plumbers bungs, fit a tyre valve to one, and bung the intake where the hose attaches to the EGR (bung the hose, not the EGR), put the bung with valve at the end of the hose that connects to the turbo, then pump it up with a bike pump that has a pressure gauge and see if you're losing boost, could be a holed pipe, intercooler, etc.
* does it have a DPF in the downpipe? Could've become clogged somehow which will seriously limit performance - disconnect the downpipe from the turbo and noisily test if things improve...
* get someone with diags to check the idle injector balances, they will be all over the shop if there's any issues with injector sealing
* check the injector lash adjusters are timed correctly - there's a line with a number on the back of the cam sprocket that aligns with a lug on the head, each number corresponds to the lobe being at full lift for the corresponding injector - the lash needs to be fully tightened then backed off one turn before tightening the lock nut.
* checking the timing is a bit more involved, because you need to be able to see that the coloured links align on the crank sprocket/chain & cam pulley/chain - all the timing pins do is lock it all in place.


All the above won't cost much to do but will help narrow down where any issue could be.

If the vehicle is otherwise sound, pity to scrap it. I would have thought there would be interest in such a project at more than scrap value.