850 2.5TDI Cold Start problem

[harveyu]

Hi. I'm new to this internet thing, but I hope someone can help me.
Got an 850 2.5TDI estate (96) with 160Kmiles and fully volvo serviced (yep, that's cost me over the years)
Anyway It now decided it does not like starting in the cold (from +8c down)
Cranks fine, manifold glowplug OK

Symptom. Cranks for about 4-5 second, and it appears to start (splutter), but stops straight away, this can be reapeated upto 20 times before it decides to run. (Throttle position makes no difference)

If you keep cranking through the initial firing it chimes in and out while cranking for upto 30 seconds (lots of black smoke, and I'm sure the starter motor hates me) before running cleanly.
(simular to a petrol engine being partially staved of fuel)

Apart from cold starting runs fine (very very well)

At a guess it's an injector timing thing, but only when it's cold ???
Is there a cold start advance which could be failing ?

Any suggestions anyone

Thanks

Harvey

[jor]

May be of no help whatsoever, but on a 940 cold start problems are usually due to either the glow plugs or the glow plug relay. Does your service record say when the plugs were last changed? If it's been a while start there, the Audi 2.5 engine manual will give instructions and a set should only cost about £30. A forum search "850 cold start" gives a couple of threads relating to diesels but the ones that I've looked at are complicated with error codes etc.

john

[tfb]

I agree with jor, I would suspect a glowplug problem before anything else. if you have a multi-meter then take the wire off each glowplug in turn and measure the resistance from the stud to earth, anything more than about 4 ohms and it's time to be changed.
Also measure the voltage supplied to glowplugs when the ignition is turned on to check that the relay is operating.

Regards
TFB

[warthog]

Hi,

generally, poor cold starts on diesels are more likely down to glow plugs, low compression etc as suggested earlier. However, on the 850's for some reason it's more often caused by poor injection pump timing. This is achieved via 2 belts (the main cam belt then a short aux. belt driving the pump). When were both the belts last changed? AFAIK these can only be correctly set-up by a Volvo main dealer and are very sensitive to mis-adjustment giving poor cold starting with lots of smoke.

Hope this helps.

[outnumbered]

Hi. I'm new to this internet thing, but I hope someone can help me.
Got an 850 2.5TDI estate (96) with 160Kmiles and fully volvo serviced (yep, that's cost me over the years)
Anyway It now decided it does not like starting in the cold (from +8c down)
Cranks fine, manifold glowplug OK

Symptom. Cranks for about 4-5 second, and it appears to start (splutter), but stops straight away, this can be reapeated upto 20 times before it decides to run. (Throttle position makes no difference)

If you keep cranking through the initial firing it chimes in and out while cranking for upto 30 seconds (lots of black smoke, and I'm sure the starter motor hates me) before running cleanly.
(simular to a petrol engine being partially staved of fuel)

Apart from cold starting runs fine (very very well)

At a guess it's an injector timing thing, but only when it's cold ???
Is there a cold start advance which could be failing ?

Any suggestions anyone

Thanks

Harvey
hi harvey
its not your glow plugs but your pump timeing is out you will have to take it to a volvo or indi to get it set up as warthog has mentioned.
mike
850tdi
v70t5

[harveyu]

Sorry for slow reply. Many thanks to all for getting back to me.
I Guessed pump / injector timing over glowplugs (thanks outnumbered) Now that suggestion confirms my thinking as follows.

a) I don't think the that 2.5 old Audi lump has glow plugs as it's a high compresion direct injection engine, Although it does have an intake manifold pre-heat (simular thing really). However last year (prior to my local dealer mucking things up (see later) it would fire straight up, no throttle, no pre heat etc at -10 and below. Just put the key in and give it a flick

b) Pump timing. Here's a great add for my local volvo dealer (I won't mention them).... It had a service and they said it had a bad oil leak which was getting on the cam belt (but no drips on the ground) I thought I'd better get it fix ASAP. The fixed the leak and put a new cam belt on (many squids). On getting it back, it ran like a dog, oh and now leaked oil ! Straight back and complained..... The oil leak which it now had, and did not have when it went if for an oil leak problem turned out just to be spilt oil on the tray which they cleaned. On checking the work they had done they spotted the second belt had not been changed, and thought that could be the poor running problem. Book in, but if broke down before getting it in. They had over tightened the aux belt idle pully which ran it's bearings and snapped. (Got on my motorbiek and gave them a real mouth full face to face. Anyway they took the car in, fixed the broken pully and replaced the pump belt. I think they just did not set the timing up correctly.

How big a job is it to set pump injector timing ?

Again, many thanks everyone for your advice

Harvey

[jor]

I'm sure the previous posts are correct about the audi engine Harvey but... there are certainly vendors on an auction site under the impression that it has glow plugs x 4!
Certainly worth your while getting your hands on the engine manual occasionally sold here, or on the aforementioned site for less than a tenner, or from Halfords if you want it quickly. DieseldDoNicely has an 850 tdi and can probably give advice.

john

[outnumbered]

Sorry for slow reply. Many thanks to all for getting back to me.
I Guessed pump / injector timing over glowplugs (thanks outnumbered) Now that suggestion confirms my thinking as follows.

a) I don't think the that 2.5 old Audi lump has glow plugs as it's a high compresion direct injection engine, Although it does have an intake manifold pre-heat (simular thing really). However last year (prior to my local dealer mucking things up (see later) it would fire straight up, no throttle, no pre heat etc at -10 and below. Just put the key in and give it a flick

b) Pump timing. Here's a great add for my local volvo dealer (I won't mention them).... It had a service and they said it had a bad oil leak which was getting on the cam belt (but no drips on the ground) I thought I'd better get it fix ASAP. The fixed the leak and put a new cam belt on (many squids). On getting it back, it ran like a dog, oh and now leaked oil ! Straight back and complained..... The oil leak which it now had, and did not have when it went if for an oil leak problem turned out just to be spilt oil on the tray which they cleaned. On checking the work they had done they spotted the second belt had not been changed, and thought that could be the poor running problem. Book in, but if broke down before getting it in. They had over tightened the aux belt idle pully which ran it's bearings and snapped. (Got on my motorbiek and gave them a real mouth full face to face. Anyway they took the car in, fixed the broken pully and replaced the pump belt. I think they just did not set the timing up correctly.

How big a job is it to set pump injector timing ?

Again, many thanks everyone for your advice

Harvey

hi harvey
your car has glow plugs five of them plus the pre heat. the [pump timing has to be set up with a scan tool whilst the engine is running i can do that for you for a small donation to my grandsons holiday pot but i am in leeds to far i think. you will have to go to a volvo dealer , indi or diesel spes. hope that helps
mike
850 tdi
v70 t5

[harveyu]

Hi outnumbered, thanks for your help, As you say leeds is a bit of long way (althouhg it might be a lot cheaper than the dealer)

I'm sure it only had a manifold per-heat not seperate glow plug, but not sure without looking.

With respect to JOR's comment about people selling 4 glow plugs for the 850. Yep I've seen those on ebay as well. It's very worrying when the 850 is a 5 pot motor. . . tee hee. Simply it's like this
a) here is clearly knowledgable and experienced
b) I have a pretty good idea
c) don't trust an ebay seller that can't count to five

Again, many thanks one and all.

p.s. outnumbered, if the 850 has "A glow plug per pot" should there be a great big cable linking them together somewhere near each injector. I can't remember seeing them or the cable (but it was a little time back when I last lifted the cover off the motor ?

[phasesonix]

hi harvey
your car has glow plugs five of them plus the pre heat. the [pump timing has to be set up with a scan tool whilst the engine is running i can do that for you for a small donation to my grandsons holiday pot but i am in leeds to far i think. you will have to go to a volvo dealer , indi or diesel spes. hope that helps
mike
850 tdi
v70 t5


Hi,

wheres the preheat glow plug?is it in the inlet?

Do you know if the 2000> V70 with the audi engine has the glow plug on the inlet?

Thanks,loz

[DieselDoNicely]

Hi,

wheres the preheat glow plug?is it in the inlet?

Do you know if the 2000> V70 with the audi engine has the glow plug on the inlet?

Thanks,loz

Unlikely to be the glow plugs, the weather hasnt been cold enough. I think they are only turned on if outside temp is less than 5 degrees (needs checking this is true, but the car does know what the external temp is).

DDN

[phasesonix]

Unlikely to be the glow plugs, the weather hasnt been cold enough. I think they are only turned on if outside temp is less than 5 degrees (needs checking this is true, but the car does know what the external temp is).

DDN


I just wanted to know where the extra glowplugs are.