D5254T (to 2002, Audi) - S80 TDI - Glow plug light / cold starts

david_940 · Dec 4th, 2010, 19:34

I have a S80 TDI 1999 with MSA 15.8. I have been having some problems with cold starts, though it is better than it was it's still not perfect!.

There are 2 problems:
1. There has never been a glow plug light when the ignition is first turned on, though the previous owner (my Dad) is sure it did have one.
2. If the weather is cold (below say 7 degrees C) it can take a few attempts to start and when it does I get a fair amount of smoke out of the back as if the glow plugs are past it.

Done so far:
1. Pump timing checked by diesel specialist - OK
2. Glow plugs checked by diesel specialist - OK
3. New fuel filter and pre-heat valve (the one way valve which sits on top of the filter).
4. New battery (correct ah etc).

Bearing in mind my technical skills are somewhat limited is there anything else I can check, I have read a bit about this and have seen some references to a glow plug relay, where is that and does it control the light coming on?
I have also read that the control starts with a temp switch, where is this and could it be causing these problems?

Thanks in advance for any advise!

Kelvyn · Dec 5th, 2010, 13:04

I'm no expert either but I have recently had trouble with my 2.5 TDi too.
I had a cam belt break and as a result had to fit a replacement engine. After a few teething problems all was well until the weather turned really cold recently. It became quite difficult to start in the mornings. Once it had been running for a while and was even slightly warm it was fine.
I assumed that there was a problem with the glow plugs that were in my replacement engine so I swapped them out for the ones from my old engine. This did improve things a little but it still required a lot of cranking and resulted in a lot of smoke when it did fire up. I bought a set of 5 plugs from my local GSF and fitted those and now it starts as well as ever.
Like you I dont appear to have a glow plug light on the dash although I thought I could remember one. I even checked my drivers handbook, it tells me that the information display tells me the engine is pre-heating (presumably the information centre that warns of any faults-- the one to the left of the cluster). I have watched this though and have seen nothing. What I have started doing is to wait for the other warning lights that come on when you turn on the ignition to go out then crank the engine, this seems to work well for me at least.
The glow plug relay is in the fuse box under the bonnet, as far as I can make out its the third one from the outside on the row nearest the front of the car.
My understanding of the temperature sensing is that the ECU gets information from the engine coolant temperature sensor, the Maf sensor and the air intake temperature sensor. The glow plug fuse is in the same box as the relay and is fuse 18. Hope some of this is helpful, the glow plugs are pretty easy to change by the way, you need a deep 10mm 3/8 drive socket and a long extension bar. You also need to remove the bracket on the power steering pump that supports the engine cover, just a couple of 12mm bolts. You need to remove that to be able to get to the plug of number 1 cylinder.

artiedtke · Dec 5th, 2010, 13:50

Quote:

Originally Posted by Kelvyn

Hope some of this is helpful, the glow plugs are pretty easy to change by the way, you need a deep 10mm 3/8 drive socket and a long extension bar. You also need to remove the bracket on the power steering pump that supports the engine cover, just a couple of 12mm bolts. You need to remove that to be able to get to the plug of number 1 cylinder.

I'm thinking of doing mine soon. This will be helpful - thanks. Just afraid of snapping any. Are they quite tight??? Did you soak in WD40 or similar first ???

Kelvyn · Dec 5th, 2010, 16:54

They are only supposed to be tightened to 15Nm which isnt much. No I didn't use WD40 on mine, they unscrewed quite easily although it wouldn't do any harm I guess. Getting the wiring off was a bit tricky, I had to use a hook to pull them off as they are tucked into the side by the injector pipes. I pulled off number 5 first then 4 and 3. 1 and 2 are seperate and are the least accessible, you just need them out of the way so you can get your socket in, they fit just like spark plug leads on a petrol car, when you re-fit them you can hear and feel them click back into place. The whole job took me less than an hour ( I was glad of that because it was -3 whenI did it). I also had the engine warmed up before I started as I figured it would help keep my fingers warm.
By the way I checked a while ago and the information centre does tell me that pre-heat is on, I hadn't noticed before because I have another warning message that comes up. I scrolled past that and sure enough there was the pre-heat one. Once that goes out you're good to go (or should be)

artiedtke · Dec 5th, 2010, 17:07

would a 1/2" drive socket be ok, i dont have any 3/8 stuff

Kelvyn · Dec 5th, 2010, 17:34

Quote:

Originally Posted by artiedtke

would a 1/2" drive socket be ok, i dont have any 3/8 stuff

You'll find its just too big to get in with 1/2 inch. If you look at the position of the glow plugs in the head you'll see you need the smallest tools possible.
Its snug even with 3/8 stuff.

david_940 · Dec 5th, 2010, 19:07

I'll see how I get on this week as it started perfectly today, strange! Just ordered some Plus Gas (apparently a better release agent than WD40), just to be sure as I once had a bad experience with some spark plugs on a Ford KA.

Thanks for the advise! By the way, I do get the "Pre Heat" message

Cheapest I found was:
http://www.amazon.co.uk/English-Abra...1575891&sr=1-1

Already got a price on the glow plugs, £7.50 ea from Motosave in Leyland, not bad for Bosch!

Kelvyn · Dec 5th, 2010, 23:46

Quote:

Originally Posted by david_940

By the way, I do get the "Pre Heat" message

It should come on in the information display (the text block on the bottom left of the instrument cluster). It should come up as soon as you turn on the ignition and stay on about 5 seconds or so. If you dont see it (like I didn't) try pressing the scroll button on the end of the indicator stalk.

BillB · Dec 7th, 2010, 12:54

My year 2000 2.5D (classic V70) has a glowplug icon bottom left of dash which comes on with ignition when temp is minus (something). If I crank the engine before it goes out it takes a while to start. If I wait until the icon goes out it starts instantly i.e. the difference is dramatic. Regards.

RoscoMac · Dec 9th, 2010, 23:13

2000 S80 tdi has "diesel pre-heat" message rather than a coil.

R.

Dec 4th, 2010, 19:34	#1
david_940 Volvo Mad Last Online: May 11th, 2024 12:16 Join Date: Dec 2001 Location: Euxton Lancashire	S80 TDI - Glow plug light / cold starts I have a S80 TDI 1999 with MSA 15.8. I have been having some problems with cold starts, though it is better than it was it's still not perfect!. There are 2 problems: 1. There has never been a glow plug light when the ignition is first turned on, though the previous owner (my Dad) is sure it did have one. 2. If the weather is cold (below say 7 degrees C) it can take a few attempts to start and when it does I get a fair amount of smoke out of the back as if the glow plugs are past it. Done so far: 1. Pump timing checked by diesel specialist - OK 2. Glow plugs checked by diesel specialist - OK 3. New fuel filter and pre-heat valve (the one way valve which sits on top of the filter). 4. New battery (correct ah etc). Bearing in mind my technical skills are somewhat limited is there anything else I can check, I have read a bit about this and have seen some references to a glow plug relay, where is that and does it control the light coming on? I have also read that the control starts with a temp switch, where is this and could it be causing these problems? Thanks in advance for any advise!

Dec 5th, 2010, 17:07	#5
artiedtke Just one more thing... Last Online: Jul 10th, 2020 14:44 Join Date: Dec 2008 Location: North Wales	would a 1/2" drive socket be ok, i dont have any 3/8 stuff __________________ '98 V40 2.0T B4204T - died... '96 855 2.5 TDI D5252T - 255,000 miles "Diesel without turbo is like a woman without boobs... sure you can drive it, but there's always something missing."

Dec 5th, 2010, 19:07	#7
david_940 Volvo Mad Last Online: May 11th, 2024 12:16 Join Date: Dec 2001 Location: Euxton Lancashire	Thanks! I'll see how I get on this week as it started perfectly today, strange! Just ordered some Plus Gas (apparently a better release agent than WD40), just to be sure as I once had a bad experience with some spark plugs on a Ford KA. Thanks for the advise! By the way, I do get the "Pre Heat" message Cheapest I found was: http://www.amazon.co.uk/English-Abra...1575891&sr=1-1 Already got a price on the glow plugs, £7.50 ea from Motosave in Leyland, not bad for Bosch!

Dec 5th, 2010, 13:04	#2
Kelvyn Junior Member Last Online: Oct 24th, 2011 09:16 Join Date: Feb 2010 Location: Luton	I'm no expert either but I have recently had trouble with my 2.5 TDi too. I had a cam belt break and as a result had to fit a replacement engine. After a few teething problems all was well until the weather turned really cold recently. It became quite difficult to start in the mornings. Once it had been running for a while and was even slightly warm it was fine. I assumed that there was a problem with the glow plugs that were in my replacement engine so I swapped them out for the ones from my old engine. This did improve things a little but it still required a lot of cranking and resulted in a lot of smoke when it did fire up. I bought a set of 5 plugs from my local GSF and fitted those and now it starts as well as ever. Like you I dont appear to have a glow plug light on the dash although I thought I could remember one. I even checked my drivers handbook, it tells me that the information display tells me the engine is pre-heating (presumably the information centre that warns of any faults-- the one to the left of the cluster). I have watched this though and have seen nothing. What I have started doing is to wait for the other warning lights that come on when you turn on the ignition to go out then crank the engine, this seems to work well for me at least. The glow plug relay is in the fuse box under the bonnet, as far as I can make out its the third one from the outside on the row nearest the front of the car. My understanding of the temperature sensing is that the ECU gets information from the engine coolant temperature sensor, the Maf sensor and the air intake temperature sensor. The glow plug fuse is in the same box as the relay and is fuse 18. Hope some of this is helpful, the glow plugs are pretty easy to change by the way, you need a deep 10mm 3/8 drive socket and a long extension bar. You also need to remove the bracket on the power steering pump that supports the engine cover, just a couple of 12mm bolts. You need to remove that to be able to get to the plug of number 1 cylinder.

Dec 5th, 2010, 16:54	#4
Kelvyn Junior Member Last Online: Oct 24th, 2011 09:16 Join Date: Feb 2010 Location: Luton	They are only supposed to be tightened to 15Nm which isnt much. No I didn't use WD40 on mine, they unscrewed quite easily although it wouldn't do any harm I guess. Getting the wiring off was a bit tricky, I had to use a hook to pull them off as they are tucked into the side by the injector pipes. I pulled off number 5 first then 4 and 3. 1 and 2 are seperate and are the least accessible, you just need them out of the way so you can get your socket in, they fit just like spark plug leads on a petrol car, when you re-fit them you can hear and feel them click back into place. The whole job took me less than an hour ( I was glad of that because it was -3 whenI did it). I also had the engine warmed up before I started as I figured it would help keep my fingers warm. By the way I checked a while ago and the information centre does tell me that pre-heat is on, I hadn't noticed before because I have another warning message that comes up. I scrolled past that and sure enough there was the pre-heat one. Once that goes out you're good to go (or should be)

Dec 7th, 2010, 12:54	#9
BillB VOC Member Last Online: Apr 24th, 2024 13:58 Join Date: Dec 2002 Location: Bristol	My year 2000 2.5D (classic V70) has a glowplug icon bottom left of dash which comes on with ignition when temp is minus (something). If I crank the engine before it goes out it takes a while to start. If I wait until the icon goes out it starts instantly i.e. the difference is dramatic. Regards.

Dec 9th, 2010, 23:13	#10
RoscoMac Scottish Section Chair Last Online: Apr 28th, 2024 22:21 Join Date: Dec 2002 Location: Ayrshire View Photos By: RoscoMac	2000 S80 tdi has "diesel pre-heat" message rather than a coil. R.

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