Starting Difficulties

[geoffc]

Hi All, Have recently aqquired a 1999 Sharan TDi...it used to start on the button every time. Now after a fuel filter change, it has to be cranked a bit, when hot , particularly if its only stopped for a few minutes, eg at its MOT yesterday!! Anyone had this before, im a bit suspicious of the Fram filter....forgot to say, also that the thermostat was also replaced. (with a faulty one) Engine running at 66degrees...measured with an infrared thermometer.

[big_kev]

My first thought with any starting problem with a diesel is the battery.....it has to be fully charged or else it will take a few cranks to start the engine...although I would have thought this would affect a cold engine more than a hot one.

 

Alternatively it could be a fuel problem....ie air getting into the system...possible if the fuel filter has been changed and something is not tightened up.

[Scorpiorefugee]

Strangely, my old S reg 110 started to do this after a major service when I assume that the filters were all changed. It has never got worse but it can be annoying if you happen to stall in slow moving traffic. I have seen other references to this problem but I've never seen any euphoric claims to have fixed it.

 

Someone must know the answer.

[geoffc]

Thanks for your replies....have checked the tightness of the connections, funnily enough a suggestion has been made ....try a genuine vw-audi branded filter! This effected a cured to the same prob for someone else!!....all this is getting expensive.

[Philwalfc]

Did you sort your problem out Geoff

[geoffc]

Not sure what the fault status is at present!....Have replaced the thermostat with another new one, temperature now normal.... Have not been driving the Sharan much over the weekend. will be out and about today, so will report back later....trying to avoid buying another new filter unless im absolutely sure of a result. Geoff

[Philwalfc]

Thanks Geoff, Your problem sounds like one of a few that I am experiencing.

[geoffc]

Update on my last post.....Have been using Sharan today, no starting problems at all. Dont want to get my hopes up too early, but I cant see what the connection between the thermostat change and the improvement in hot starting might be!! Geoff

PS Just currently running a few tests on the Sharan....Will warm up the engine till the fan comes on, switch off engine, let it sit for 10 or 15 minutes, then try restarting...if all ok, will drink the bottle of wine that a customer supplied today as a thank you!

[geoffc]

Update on last post....test completed......bottle of wine almost finished, appears to be a result! geoff

[geoffc]

OOPS Shouldnt have drunk the wine so soon!! My problem is still here....will change the fuel filter again, then im out of ideas!

[Philwalfc]

Hi Geoff, Having read a good few posts on this problem, I am leaning toward the coolant temp sensor. I am getting one localy, not from 'frauds' as they are double the price. Should get it over the weekend. I'll let you know how I get on.

[Delboy255]

Hi All, Have recently aqquired a 1999 Sharan TDi...it used to start on the button every time. Now after a fuel filter change, it has to be cranked a bit, when hot , particularly if its only stopped for a few minutes, eg at its MOT yesterday!! Anyone had this before, im a bit suspicious of the Fram filter....forgot to say, also that the thermostat was also replaced. (with a faulty one) Engine running at 66degrees...measured with an infrared thermometer.

Hi Geoff,

 

Assuming this only started only after the filter was changed I would recheck all connections etc. Is there air bubbles flowing through the translucent piping at the fuel pump? This was an issue for me a number of times over the past 8 years. Would always use the correct thermostat in any case.

 

My own galaxy is now approaching 310,000 miles and has been a poor hot starter for the past few months and would alway start instantly when cold. The starter recently packed up and a new starter has solved this issue. At no time did the starter seem lazy (slow) to turn over the engine.

 

Apparently, some starter issues can be checked with VAG-Com software by switching to Auto Gearbox mode (if yours is manual that is) ?

 

 

Good Luck.

[geoffc]

Keen to put this one to bed!! Today my local mechanic was driving the Sharan when the starter failed....after I stopped laughing...we are having the starter reconditioned on Monday! Am 99.9% sure this will fix the starting problem. Geoff

[marinabrid]

had exacalty the same starting prob with our 110 even though it had new fliters etc new clamps it was still a sod to start from hot or even if you started it from cold and turned it off aftetr a few seconds it would have to be cranked for ages, cured it by smearing a graphite grease all over the top of the fuel filter pipes and where ever you could see a join in the fuel pipe system been starting well since that done.

[geoffc]

Hi All!! Starter now repaired, car still difficult to start when hot. The engine starts perfectly when cold, starts fine too when at 90 degrees.....I've found that letting the engine cool to about 65 degrees, then the engine has to be cranked for about 15 seconds for it to start. No smoke, so I suspect the problem is electronic. The temperature sensor was replaced at the same time as the thermostat.....I'm thinking I might have a software problem. Not sure that I can try next, there must be some way to test the ecu.....Much scratching of head!! Geoff

[geoffc]

According to the varta website....I may have the wrong battery fitted. The Halfords Calcium requires a charging voltage of 14.8.... the Sharan delivers 14.2....cranking speed is a bit low, will purchase a standard lead acid type 90 amp hr etc and see what happens. G

[seatkid]

Don't think changing the battery will make any difference.

[geoffc]

Have been looking at the TDI forum.....Our American cousins are having similar problems, to be exact....23 pages of them, but only with 1999 model year 1.9 litre 81Kw Diesels (AFN etc)...they have cured the problem in three ways.

Some have replaced the engine earthing cabling with heavier stuff....One replaced the starter motor with a different model, others have had the ECU reflashed with different software. The reason the engine starts ok when cold, is because when the coolant temperature sensor is indicating to the ECU that the temperature is low, the injectors inject fuel....immediately the engine starts to crank. When hot however, the ECU does not open the injectors unless the cranking speed is over 250rpm. Looking at my rev counter (not that accurate in sure) im getting a reading about 200rpm cranking when hot!

A useful bit of info...the battery leads should have a voltage drop of about 250mV per lead....or 0.5volt drop at the starter motor. I havnt been able to test the leads yet, needs two people!! Will have a chat with my local VW agent after the hols....more than likely there is an official software fix for it, as it affects 1999 Audi A4, VW Golf, Passat etc

[Philwalfc]

This is getting weird. I have been running around with the temp sensor disconnected for a week and the starting whilst warm was great. So I got my new Temp Sensor from GFS and fitted it 2 days ago. Driving around the last couple of days and the warm starting problem is back. So Tonight I disconnected the new temp sensor and hey presto starting whilst warm is great again. Firstly, Does this mean my new temp sensor is faulty, and secondly are main dealer parts better and more reliable.

[seatkid]

Its the wrong trousers! temperature sender!

 

GSF has lots of wrong items listed, just check VWsharan vs Seat Alhambra and you will see what I mean. Wrong length belts etc. No problem for me as the local gsf is only 1/2 mile away. But for something like a sensor, I would always go to my VW dealer (not my Seat dealer) as they check reg no. to get engine no. to get correct part.

 

AFAIK there are at least 3 different temperature sensors....

[Philwalfc]

Nice one Seat. A bit of false economy me thinks. Main dealer here I come.

[geoffc]

Sounds like exactly the same problem as I have...Ur cold starting is ok because at cold , the engine rpm are not monitored by the ecu....I'll bet ur engine cranking speed is just under 250rpm when hot!!

Will contact my main dealer next week when he reopens, re possible software fix.... is ur vehicle 1999 model year??BTW disconnecting the temp sensor fools the ECU into the cold start routine!...fuel consumption will be quite high...the new current genuine VW temp sensor is coded with a blue band....the old one was coded yellow Geoff

[Shabazmo]

car still difficult to start when hot. The engine starts perfectly when cold, I had the same problem but when the starter motor failled and replaced with a new one, the Galaxy worked perfectly. Doesn't make sense, but the starter motor did it. I alaso disconnected teh cold temp sensor and founmd that it cured the problem and when I fitted a new one from Ford, the problem remained. I recon that the recon starter was a mistake. try fitting another starter.

 

Regards

[geoffc]

When you replaced your starter motor, was the replacement exactly identical? What I mean is, were the Bosch part numbers the same on both units? Its not uncommon, if there is a problem with a particular part, to have VW supply an upgraded replacement....but with a new part number! I would bet your cranking speed is higher with the new unit....needs to be over 250rpm when hot, otherwise engine wont start. Will try and have a chat with the local VW parts dept tomorrow, they are normally extremely helpful. Geoff

[cbrpaul]

Hi Guys ,

 

 

I have a AFN sharan , and it too has the hot start problem,

 

I think the 250rpm thing is the problem ,

 

 

the starters work however over the years they just wont hit the 250 mark ,

 

A recon starter may still not reach the 250rpm ,,

 

 

Geoffc, did you solve the issue m8 ?

 

any info be geat !!!

 

cheers

 

Paul