peugeot TD compression issues revisited

jgra1 · Unread post by **jgra1** » 05 May 2007, 15:14

Hi all just another post regarding TD engine problems.
engine stopped at a roundabout when owner was pulling out.. no obvious noises I was told..

A summary of the problem:
Engine turns over sounding like a motor i.e. no compression.

Previous checks
Timing belt has not slipped
no strange noises
Camshaft Turns

what I have done today is

Checked woodruffs, camshaft and crank ones are fine
Checked fuel from injector pump, finger over pump outlets proved pump is pushing fuel out at high pressure in pulses
hand over inlet manifold entrance, very little vacumn
hand over exhaust, very little coming from that too..
no signs of head gasket leakage
took all glow plugs out, when turning over on starter, a low pressure escape of air from all, and the engine did not sound any different with them out.. i.e. the compression seems so low the taking them out made no difference.

just does not sound like a car engine, and certainly miles from starting..

also, when the owner had this problem, it just happened , i.e. no warning

going to condemn the old car to the graveyard, but just annoyed I dont know what happened

John

matt · Unread post by **matt** » 05 May 2007, 18:53

It is worth wipping the head off to check valves etc?

Could it be the rings?,strange to all go at once though.

Good luck!

jgra1 · Unread post by **jgra1** » 05 May 2007, 19:12

thanks Mat could not agree more..

cant be bothered

AndersDK · Unread post by **AndersDK** » 05 May 2007, 20:17

john -

My wreck BX TD suddenly stopped during a weekly warm-up run at tick over. I have not yet succeeded in getting it started.
The symptoms was exactly to your description :
1) sudden calm death just like key was turned off
2) no strange noises at all
3) after a few spin overs the engine now sounds exactly like a powerdrill
4) no smoke from exhaust - i.e. no signs of burnt or unburnt fuel

I'm pretty sure the fuel supply is lost - either by a sudden leak (the bulb primer membrane have been replaced before) - or by the fuel stop solonoid blocking.

At first I was on the same track as you thinking major disaster - because of the strange powerdrill spinning. But then I remebered that I'e heard this before - on an empty runned diesel.

A squirt of startgas is the best faulttracer you can get

If anything else but the fuel admission is working - the engine will instantly but shortly spring into life using startgas

thorter · Unread post by **thorter** » 05 May 2007, 22:17

Sounds like the fuel stop solenoid is open circuit. If it is an old Lucas pump, the solenoid coil is a plastic moulding, and relies on luck for the internal ground connection. The closure is by crimping, and there is no spring to take up any eventual settling.

You can unscrew the solenoid body, remove the stop valve, and replace body. If the engine then runs, you can use the stop lever until you get a replacement.

Unread post by **CitroJim** » 06 May 2007, 09:55

It could also be caused by very old and contaminated diesel, especially if it has run on veg. oil at any time and then been left standing for a considerable time.

Old diesel and especially old veg. oil does not burn at all well.

jgra1 · Unread post by **jgra1** » 06 May 2007, 11:09

thanks all..

Fuel is spraying out of the injection pump from all four outlets,, have powered the solenoid seperatly and it clicks.. but the fuel coming out under pressure makes fueling seem unlikely now?

She used the car daily as a horse tower, and always had loads of fuel in tank, from garages etc..

but the glowplug removal bit, surely that proves compresion is gone?
hmm

Unread post by **CitroJim** » 06 May 2007, 11:37

Certainly looks like the compression has gone.

Have you tried doing a "wet" compression test by putting oil into the cylinders? This will quickly determine if the rings or valves are causing the problem; the oil will provide a temporary ring seal and boost compression.

Back in the old days, before glowplugs, some diesels were started by squirting oil in the bores to both imropve cold ring seal and bump up the compression ratio a bit. Squirt some in down the glowplug holes (difficult I know) and then try a start-up. The seal given by the oil and the slightly higher compression may just spark it into life and then once oil gets circulating, all may come good.

fastandfurryous · Unread post by **fastandfurryous** » 16 May 2007, 19:55

Given that this engine has naff all compression, on ANY cylinders, there's only one thing really that it can be: major internal failure.

Either the Head gasket has failed so badly that the engine can't run, or it's overheated so badly that the combustion chambers have melted out into the coolant passages. I've seen this happen once before.

If it were camshaft related, there would be compression on at least one or two cylinders.
If it were piston/ring related, there would be at least some compression, just not enough.
And It's not fuel related.

It would be interesting to have the head off though and see what has happenend.

Brian UK · Unread post by **Brian UK** » 16 May 2007, 23:03

The other way to find out is to do a leakdown test. Put cylender at TDC with valves closed, and connect a compressor to the glow plug hole. Then listen to where the air leaks out. Do same for each cylender.