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Mercedes Benz Sprinter 2004 - Fails to start hot #

Posted by Alan Kane on May 26, 2011, 1:00 pm

Year of Manufacture *: 2004
Engine Size and Code *: .
( Optional ) Scanner Used: Star

Mercedes Sprinter
WDB90366332R523931

Symptom – Fails to start very occasionally. Only happens when engine is hot. Other than this it drives perfect with no running concerns. Never stalls.

P1482-004 Glow output stage
P1481-002 Glow plug cyl 2
P1481-008 Glow plug cyl 4
P1354-002 Sync between crank and cam – freq of cam signal too high
P1354-016 Sync between crank and cam – no crank signal
P1354-064 Sync between crank and cam – no cam signal

I had this van for 24 hours, drove it, started many times, never failed to start. Cleared the codes and gave it back to the customer. He returned with it having failed to start for him once. Same codes logged again but still will not fail for me.

The ambient data for the codes show engine speed as zero. Wiring checks ok.

Is there an interference issue with these or is it a simple sensor fault (cam or crank)? Is the code setting criteria just a bit odd and so complicating matters?

TIA

Alan

Re: Merc / Sprinter / 311 / fails to start hot

Posted by Dave Hill <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT2783' width='330' height='300' border=0 style='border:none;'> on May 26, 2011, 4:35 pm, in reply to "Merc / Sprinter / 311 / fails to start hot "

Hi Alan

This post seems a little out of character for you. (almost like you are testing the UKAT crowd

)

Glow device codes aside, surely everything is pointing toward a crank sensor (heat soak) failure.

If I wanted to see & confirm the fault, I would be cruising the revs in the workshop for an hour and then scope the crank sensor after it has stood for ten minutes.

Truth be told though, I would probably just stick a new sensor in, based on the info given alone.

Have I missed something?

Cheers

Dave

Re: Merc / Sprinter / 311 / fails to start hot

Posted by Alan Kane <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT5535' width='330' height='300' border=0 style='border:none;'> on May 26, 2011, 7:27 pm, in reply to "Re: Merc / Sprinter / 311 / fails to start hot "
Alan Kane - Administrator

Hi Dave,

No, not trying to test anyone. I could however be over analysing it.

I have seen a few mercs with cam/crank sync codes that had no relevance to the actual faults and wondered why they were logged, as you do. A mate of mine suggested they could log due to excessive cranking. If that happened to be true in this case it could mean I have no relevant fault codes. Like I said, probably over analysing it, but I am interested in why a ckp, or even a cmp, would log those particular codes.

Something I forgot to post, I did scope this, crank v cam, while hot and it was perfect. It was of course starting perfectly at the time as well. From what I can gather this has been going on for quite a while and I would have expected a ckp to have gotten worse or failed by now. I have ordered a ckp as its probably the most likely candidate.

Cheers

Alan

Re: Merc / Sprinter / 311 / fails to start hot

Posted by colin jelf <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1635' width='330' height='300' border=0 style='border:none;'> on May 26, 2011, 7:44 pm, in reply to "Merc / Sprinter / 311 / fails to start hot "
Colin Jelf

hi alan
i know you said wiring checks ok but i did have a very similar fault to this that turned out to be loom chaffing through on nearside engine mounting only visible when unclipped & pulled away from mounting.also check the normal carbon build up around leaking injectors will ruin loom if this has happened.one other commmon starting fault is o rings on fuel system.
hth colin

Re: Merc / Sprinter / 311 / fails to start hot

Posted by aidan birley <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT2879' width='330' height='300' border=0 style='border:none;'> on May 26, 2011, 7:53 pm, in reply to "Re: Merc / Sprinter / 311 / fails to start hot "
Aidan Birley

Alan

I to have seen that code without any related issue. what sort of mileage has it done, possible chain stretch issue?

Would be worth an injector leak test, It may just be hovering around threshold and hot derv tipping it. In my experience the O rings fault is more consistent but no harm in looking.

Although always nice to prove a fault, with intermittent crank / cam sensor it is sometimes difficult to justify diagnostic time as opposed to substitution.

Cheers Aidan

Re: Merc / Sprinter / 311 / fails to start hot

Posted by Dave Hill <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT2783' width='330' height='300' border=0 style='border:none;'> on May 26, 2011, 8:41 pm, in reply to "Re: Merc / Sprinter / 311 / fails to start hot "

Hi Alan

I am guilty too of over analysing things. I tend to place more relevance in DTC's from German vehicles than French stuff though. So I do know why you want to understand the code set criteria.

Have you followed the guidance in Star?

Re: Merc / Sprinter / 311 / fails to start hot

Posted by Alan Kane <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT5535' width='330' height='300' border=0 style='border:none;'> on May 27, 2011, 8:04 am, in reply to "Re: Merc / Sprinter / 311 / fails to start hot "
Alan Kane - Administrator

Hi all,

Colin, The wiring is mint. I didn’t cut the loom open but its certainly not gone in the usual manner. O rings, in my experience at least, will always log fuel pressure/control codes as will leak off after multiple occurrences.

Aidan, There are 5 or 6 possible versions of the code. I have 3 logged. We may not have the exact same codes. Are you saying yours was caused by a stretched chain? When this starts, either after it has failed or when it starts normally, it is instantaneous. When running it is perfect with very stable fuel control, nothing like a vehicle with control issues. The symptom appears to be more heat related.

Dave, Strange, analysing is spelt with the word anal at the beginning (aimed at myself, not you). I should probably learn something from that.
Yes, star directs checking the wiring, reluctor rings and then replacing the sensors, both ckp and cmp. 2 out of the 3 codes blame the cmp but the ambient data shows zero engine speed when they logged.

Its getting a new ckp later today which will probably fix it. If not I will look further.

Alan

Re: Merc / Sprinter / 311 / fails to start hot

Posted by aidan <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT2879' width='330' height='300' border=0 style='border:none;'> on May 28, 2011, 3:17 pm, in reply to "Re: Merc / Sprinter / 311 / fails to start hot "
Aidan Birley

Hi Alan

The stretched chain was just a suggestion to consider.

Can't remember the exact code description, but was not investigated as not causing any problems.

yours does sound more like a Crank sensor issue, but sods law say's they wont fault with a scope hooked up

cheers Aidan

Re: Merc / Sprinter / 311 / fails to start hot

Posted by Alan Kane <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT5535' width='330' height='300' border=0 style='border:none;'> on June 1, 2011, 10:00 am, in reply to "Re: Merc / Sprinter / 311 / fails to start hot "
Alan Kane - Administrator

Just to update this. I had the van again for a few hours and tried to make it fail but it started perfectly. Fitted the new ckp, gave it back yesterday, just had a call saying it failed again already this morning.
The customer had been informed that the part was being fitted based more on educated opinion than positive test results and if it failed again he would be faced with paying for more testing and being without the van for longer.

This brings me back to my inital thoughts that those codes could be red herrings because I have seen similar before. Getting it to fail and testing it is the only way forward as far as I am concerned. Hopefully my next update wil be a fix.

Re: Merc / Sprinter / 311 / fails to start hot

Posted by Kevin Gundry on June 1, 2011, 10:47 am, in reply to "Re: Merc / Sprinter / 311 / fails to start hot "
Message modified by board administrator June 1, 2011, 7:29 pm

Hi Alan, only just seen your post. i have had this problem before, get the engine up to operating temp with a test drive, then scope the camshaft sensor, all the ones i have done drop out after about 15 mins. this engine only needs cam signal to start if it drops out when the engine is running it will keep running

It's quite a common fault on sprinters they have modified the part about 3 times from memory ( touch wood i never see them back after and they are on our fleet )

i normally test the wiring through then replace both parts because all the one's i work on must be good vans they have been to the moon and back several times.

HTH
Kev G

Re: Merc / Sprinter / 311 / fails to start hot

Posted by Alan Kane <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT5535' width='330' height='300' border=0 style='border:none;'> on June 2, 2011, 7:54 am, in reply to "Re: Merc / Sprinter / 311 / fails to start hot "
Alan Kane - Administrator

Hi Kevin,

Thanks for the reply. While I scoped it, the cmp signal was perfect but perhaps I didn’t scope it for long enough. When I get it back I will put more effort into watching the cmp. I will update after I see it again.

Cheers

Alan

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