Audi A5 Forum & Audi S5 Forum banner

21 - 36 of 36 Posts

·
Registered
Joined
·
30 Posts
Discussion Starter #21
Thanks eamonn actually a friend was saying to try a spare battery and jump leads to try and help with the existing battery still connected. Will try tomorrow
 

·
Registered
Joined
·
54 Posts
Did you find issue. I’ve had same problem for about 6 months now changed all sorts car is in garage atm getting injectors tested and they have rang to say 2 are completely buggered and the other 4 are on way out it’s only done 40000 miles
 

·
Registered
Joined
·
30 Posts
Discussion Starter #24
Injectors leak back test came back ok and values on Vcds. I bought new injector and they went though all cylinders in case it was small leak which wouldn’t show up. I put new battery on aswell as it was the original Audi battery ( I think ) would have made it 11 year old. Fault scan showed codes for ALL glow plugs but my mechanic said these engines only use them temps as low as -7 degrees.
 

·
Registered
Joined
·
91 Posts
Following a little research......

Ok had some time on my hands sitting on a train....so I took it upon myself to do a little research on this. A little back round…….I had A VW 2.0 TDI with long crank that was fixed by correcting a drain back to the tank overnight with check valves. I also fixed a non-smooth start up by changing the starter motor.

The 3.0 TDI is popular so I check across the Audi range of models….the Q7 was most popular.

Ok what came back with a bunch of bloggers was….drum roll……starter motor….I know a big let down….but stay with me.

One fella changed all sorts, battery, then OEM battery, more stuff etc…reacting to advice after advice, still the 10 second crank perhaps 2 or 3 time before start-up then fine until the car sat for a while, usually overnight. No fault codes. In the end it was taken to a Audi dealership (I know - what *uckin good will that prove, however luck was on this fellas side). It was diagnosed with two problems (one unrelated and we will ignore) the starter motor was out of spec. and they tested it by checking the amps during start-up, in this case it was too high meaning the starter was stiff internally due to the gearing that is inside the motor assembly. The motor got changed out and our man is a happy chappy.
I read three blog posts about this with the same outcome……changed things willy-nilly, no change then changed the starter and everything was grand.

Info I picked up – It needs to spin at a minimum of 280RPM. Below this no good, poor starts, long crank….its seems very sensitive.

So how can you check, you cannot get any information from VCDS during cranking or just after?...well the Audi tech used starter motor current (amps) but I don’t know what it should be.
A second method is you need a scope and use the crank sensor and some software maths to get the frequency.

A third method is that good people with a 3.0 TDI on this forum can perhaps record their good start audibly as we all have phones or provide the current if you have the equipment. The people with bad starts could do the same. The bad starters should listen to recordings carefully as the difference is no huge and judge if they are going to call the parts department.

Do not repair starter motor, new only. The problem is the gearing gets stiff, it not the bushes and commutator that a repair will look at.

Perhaps a good blogger could put together a blog post that the TDI owners can contribute toward with their cranking amps. So we can all check going forward as this will happen to all TDI cars in the end.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #27
Hi idua some great research there thank you- I to seen a lot of ppl saying they cured the 10 sec crank with a new starter motor but one symptom that they did all have a lot of smoke when the car did finally start - which mine doesn’t. Also now Mine sometimes starts after 4sec with you pump accelerator a bit before cranking!

It’s really strange and I can’t really afford to leave in to garage for diagnostics and guessing parts anymore unfortunately! ESP as the car drives perfect I think I’ll have to live with it!
 

·
Registered
Joined
·
30 Posts
Discussion Starter #29
Yes maybe not a bad shout but I’ve spent a grand on it in the last 4 months so no more!!! Hope it works for you mate
 

·
Registered
Joined
·
1 Posts
Hey man! I got exactly the same problem on my old audi. It is very difficult for me to start the engine. It starts only after 3-4 tries, and, once started, the problem disappears! I am fighting with that problem for many years, and I still didn't fix it. I thought that the problem is in the empty battery, and I tried to jump start it as written in this article Ultimate Guide On How To Jump Start A Car – OtO PartShop, but it didn't help. What can it be ?!
 

·
Registered
Joined
·
54 Posts
Hey man! I got exactly the same problem on my old audi. It is very difficult for me to start the engine. It starts only after 3-4 tries, and, once started, the problem disappears! I am fighting with that problem for many years, and I still didn't fix it. I thought that the problem is in the empty battery, and I tried to jump start it, but it didn't help. What can it be ?!
Hi

I had this problem for 2 years. Turns out the Starter motor changed it and it’s been fine ever since. I changed battery injectors,fuel pressure sensor etc turns out starter wasn’t turning fast enough and it was an old Audi mechanic diagnosed straight away. It had been into Audi 3 times and they couldn’t believe it when a told them it was starter
 

·
Registered
Joined
·
3 Posts
Has anyone considered old battery may be cause. We had similar situation when battery was past expiry date. These vehicles don't seem to do the classic weak turnover sound when low, they sound like they're cranking fine and strong, it just takes a while.
 

·
Registered
Joined
·
54 Posts
Yeah I changed my battery and made no difference like a say mine was a weak starter motor common problem on the 3.0 tdi engines especially on the q7
 

·
Premium Member
Joined
·
1,998 Posts
Do not underestimate the Power of the Battery guys. The A5 seems to be hyper-sensitive to the state of charge of the battery as well as to the brand!! AND they require coding to the car, which I have never understood. So always consider the possibility that the battery is playing uo, and it does not even like jump starting from another battery....
 

·
Sponsor
Joined
·
2,365 Posts
Do not underestimate the Power of the Battery guys. The A5 seems to be hyper-sensitive to the state of charge of the battery as well as to the brand!! AND they require coding to the car, which I have never understood. So always consider the possibility that the battery is playing uo, and it does not even like jump starting from another battery....
Fortunately coding isn't absolutely required, it just enables certain power management features.
 
21 - 36 of 36 Posts
Top