Hello I have a Expert Series 1 van with XUD9T engine (DHX is code on the block) which smokes a little and am looking for some ideas of possible cause.
It is an 18 year old (T reg) turbodiesel with 44k on the clock which could be right but we have no history to confirm or disprove this. I have owned it for 4 years and it is a good drive which goes, steers and stops nicely. A couple of years ago we had a starting problem cured by replacing the glow plugs. Later that year we noticed that it was smokey under some conditions, most noticeably when standing ticking over for example in a traffic queue.
Our usual garage suggested we have a compression check but did not have the required adaptor to suit the XUD engine. We had a diesel specialist look at it. They diagnosed a misfire and smoke at certain engine speeds and did the following:
Compression Test OK: No.1 Cyl 34 Bar; No.2 32 Bar; No.3 32 Bar; No.4 33 Bar. Greatest difference = 6 %
Tested injectors: No.1 sticking, rest OK. all cleaned and No.1 reconditioned with new nozzle.
Re-assembled with all new copper and heat shield washers and leak off pipes. Still misfires and smokes. Replaced diesel filter and bled system - problem not solved.
Removed injectors re-tested and proved OK.
Bosch diesel pump removed and taken to approved Bosch diesel service centre. Test found erratic fuel delivery and fuel residue in pump appears contaminated. Pump was flushed to clean out residue (Diesel expert asked if I had run it on veg oil, I hadn't but previous owner may have).
Pump refitted with new timing belt kit, fuel pump plunger travel set to 0.66 mm.
Ancillary parts replaced, fuel conditioner added to tank and engine run. About 20 litres of Shell V-Power added to tank, test driven and found OK.
I collected the van and it appeared to be ok, misfire gone although still a little smokey but it is an older diesel and nowhere near as dirty as the buses I see around.
By coincidence I had a conversation with a person who claimed knowledge and experience of diesels and who suggested we might have had the Diesel Bug problem. Bought some Diesel Bug Treatment and added to tank, all seemed OK. We didn't use it much last year but used it this week and would like to find the cause of the problem and we hope fix it.
I decided I needed to rule out contaminated fuel so arranged a temporary supply from a 5 litre can of clean diesel from a busy filling station. No improvement, the symptoms are that the engine produces white(ish) smoke when the coolant temperature is less than about 90C. If I drive it till the engine is at working temp and park with the engine idling the exhaust is clear for about 30 seconds then produces thin white smoke as the temp gauge falls back to about 75C. If I rev the engine and bring it back up to 90C the smoke diminishes to barely visible.
I would assume that whiteish smoke would indicate firstly unburnt diesel or some oil being burnt or a leak into the engine from the cooling system. The last two times I checked oil consumption it had used 0.7 L of 10W40 in 760 miles and just less than a litre in 1254 miles. PSA say I litre of oil per 600 miles is OK.
The cooling system hardly needs to be topped up at all.
I will check for oil and water use again to confirm they have not worsened and test the thermostat to see that it opens and closes at the correct temperatures. I am wondering about incomplete combustion due to overcooling? Maybe a turbo bearing seal allowing a small amount of engine oil to leak into the intake air? Beyond that I don't have any definite ideas other than a cylinder head problem, the gasket but that should get worse and be obvious by water loss or a crack in the head itself?
Please post your ideas or a solution if you have one as I need to decide what to do with it! Thanks in anticipation.
It is an 18 year old (T reg) turbodiesel with 44k on the clock which could be right but we have no history to confirm or disprove this. I have owned it for 4 years and it is a good drive which goes, steers and stops nicely. A couple of years ago we had a starting problem cured by replacing the glow plugs. Later that year we noticed that it was smokey under some conditions, most noticeably when standing ticking over for example in a traffic queue.
Our usual garage suggested we have a compression check but did not have the required adaptor to suit the XUD engine. We had a diesel specialist look at it. They diagnosed a misfire and smoke at certain engine speeds and did the following:
Compression Test OK: No.1 Cyl 34 Bar; No.2 32 Bar; No.3 32 Bar; No.4 33 Bar. Greatest difference = 6 %
Tested injectors: No.1 sticking, rest OK. all cleaned and No.1 reconditioned with new nozzle.
Re-assembled with all new copper and heat shield washers and leak off pipes. Still misfires and smokes. Replaced diesel filter and bled system - problem not solved.
Removed injectors re-tested and proved OK.
Bosch diesel pump removed and taken to approved Bosch diesel service centre. Test found erratic fuel delivery and fuel residue in pump appears contaminated. Pump was flushed to clean out residue (Diesel expert asked if I had run it on veg oil, I hadn't but previous owner may have).
Pump refitted with new timing belt kit, fuel pump plunger travel set to 0.66 mm.
Ancillary parts replaced, fuel conditioner added to tank and engine run. About 20 litres of Shell V-Power added to tank, test driven and found OK.
I collected the van and it appeared to be ok, misfire gone although still a little smokey but it is an older diesel and nowhere near as dirty as the buses I see around.
By coincidence I had a conversation with a person who claimed knowledge and experience of diesels and who suggested we might have had the Diesel Bug problem. Bought some Diesel Bug Treatment and added to tank, all seemed OK. We didn't use it much last year but used it this week and would like to find the cause of the problem and we hope fix it.
I decided I needed to rule out contaminated fuel so arranged a temporary supply from a 5 litre can of clean diesel from a busy filling station. No improvement, the symptoms are that the engine produces white(ish) smoke when the coolant temperature is less than about 90C. If I drive it till the engine is at working temp and park with the engine idling the exhaust is clear for about 30 seconds then produces thin white smoke as the temp gauge falls back to about 75C. If I rev the engine and bring it back up to 90C the smoke diminishes to barely visible.
I would assume that whiteish smoke would indicate firstly unburnt diesel or some oil being burnt or a leak into the engine from the cooling system. The last two times I checked oil consumption it had used 0.7 L of 10W40 in 760 miles and just less than a litre in 1254 miles. PSA say I litre of oil per 600 miles is OK.
The cooling system hardly needs to be topped up at all.
I will check for oil and water use again to confirm they have not worsened and test the thermostat to see that it opens and closes at the correct temperatures. I am wondering about incomplete combustion due to overcooling? Maybe a turbo bearing seal allowing a small amount of engine oil to leak into the intake air? Beyond that I don't have any definite ideas other than a cylinder head problem, the gasket but that should get worse and be obvious by water loss or a crack in the head itself?
Please post your ideas or a solution if you have one as I need to decide what to do with it! Thanks in anticipation.
