badly smoking Bongo

[Jacqui]

Yesterday the bongo began to smoke when ticking over. (it's a 2.5 diesel).
The smoking was preceeded with the engine starting a little bit rougher than normal and taking a short while before it would run smoothly (almost like it was running on three cylinders at start).

The smoke is white in colour and is only apparent when the engine is at tick over, once on the move the smoking stops.
The car runs ok with no apparent loss of power.
I've treated with diesel injector cleaner and ran for about 50 miles but it's still the same.
The engine is running on diesel although I have used a veg oil mix a couple of months back.
It's at the point where it can't be used because of the smoke that's chucked out at each junction I stop at.

Does any of this make any sense to anyone? I live in an area where there are no real Bongo capable garages so I would really appreciate any advice before I take it into a non-Bongo mechanic.

[maxheadroom]

Sounds like it could be oil seals on the valve stems, when the engine is at tickover pressure drops and oil can run down the valve stems. We had a golf like this, fitted new seals and all was ok.

Or have you over filled the oil?

[astrobyker]

Or turbo oils seal. Has the coolant level dropped at all?

Jes

[mister munkey]

Mine played up a bit in the early days. Seems I had a weak glowplug or two.

Leaving the key turned an extra few seconds after the g.plug light going out cured the lumpy start & initial smokey rough running for the first few seconds.

It was also burning a bit of oil to start with - using around a litre every 1500 miles or so. This has been solved, temporarily, by using Wynns Stop Smoke at each oil change.

Its a gloopy gold coloured bottle of stuff, chucked in with each change.

Its obviously not cured the fault but has cut the oil consumption to zero & cleaned up the smoke problem.

Try it before spending serious dosh.

[Steve L]

Surely if it was burning oil the smoke would be blue not white. Could the problem be EGR related?

[mikeonb4c]

Surely if it was burning oil the smoke would be blue not white. Could the problem be EGR related?

I wondered about that too. Whereas atomised diesel that had not burned completely might well produce white smoke (remember how the old Primus stoves would put out clouds of paraffin smoke until the lit up properly). This would be consistent with glow plug problems

[Simon Jones]

I wouldn't have thought glowplugs are likely to be the problem as jacqui says its happening at every junction: glowplugs are only powered up for the first few monents after start up. White smoke it usually associated with water/steam in the combustion chambers. While I was having head gasket problems, I would often get white smoke & lumpy running at start up as the water that had accumulated overnight was burnt off.

Suggested checking if the coolant level is dropping (or increasing) with use. The other option is to take it for a 'sniffer test' which will confirm/exclude the presence of water in the exhaust.

Fingers crossed its nothing to tricky to sort out.

[Jacqui]

Thanks for the suggestions. I've done a bit of investigation and found that the oil level doesn't seem to have dropped but I have used coolant (with no other leaks apparrent).

I am thinking head gasket or turbo seals maybe? If it is turbo seals can they be replaced?

[bigdaddycain]

It's sounding suspiciously like the head gasket i'm afraid jacqui.... Is there any evidence of water in the oil? (mayonaisse type substance on the inside of the oil cap, or on the end of the dipstick?)

Is the coolant a murky colour? Is the expansion tank looking stained?

[Jacqui]

The expansion tank has always been stained since I bought the car, the oil doesn't look emulsified on the filler cap or dipstick. Still puzzled as to why it only smokes when up to temparature and at tickover.
The only certainty is that the coolant level has definitely dropped.

[Simon Jones]

From my investigations, I have never heard of a Bongo which has any signs of water in the oil, although it is a classic symptom in more 'traditional' vehicles.

The problem area on the gasket is between the cylinder bore & the water jacket - this is the point which get hottest & has the greatest pressure.

On the other hand, it could be a cracked head. The reason it would only be apparent at operating temperature is because any crack would tend to open up as the aluminium expands. There has been loads of posts on here covering head & gasket failure, but one tip is to get the head pressure tested by a workshop that can get it up close to temperature, as otherwise cracks can go undetected.

[Jacqui]

Thanks again for all of your replies. The story has moved on a page or two now.
Took the Bongo to a mate's mate who has a garage, he suspected cylinder head gasket or head cracked.
He removed the head found the gasket to be intact and could not find any trace of coolant in any of the cylinders, he asked for a second opinion from a diesel fitter who agreed that all looked to be ok
He was due to go on holiday so I agreed to take the head to Cleasby's, who he had recomended, for a pressure test.
They took a look at it on the shop counter and immediately recognised it as a Mazda head and within seconds told me that No. 1 chamber had definitely had coolant in it I asked how they could tell to which the bloke replied "39 years of experience" he went on to say that with metalised gaskets it wasn't always obvious that the gasket was leaking so it could be a case of a warped head or ,worst case, a crack.
They don't work weekends so I'll find out on Monday, if it is only out of shape it'll be £65 + vat for the pressure test & skim.
Fingers crossed then.
Another question: If I have to buy a new cylinder head is there anywhere you could recommend or is there anywhere I should avoid? There are a few on Ebay but I am not confident of their pedigree.

[Bob]

Phil at JAL sometimes has to odd Bongo breaking, as do Bell Hill garage near Bath. Good luck.