Hot Start Fix - different angle

Just a little observation on the P38 DSE Hot start problem.

My 98MY DSE was getting progressively worse at hot starting over the last few months. I was reluctant to fit the 'Fix' as back when I researched it a few years ago I remember coming across a thread going into the possible problems associated with doing the coolant sensor fix.

Anyway with the onset of the cold snap before Christmas it got so bad that i couldn't trust it so I went looking for one of these mythical Optima red top batteries. At this stage I was often only getting a click out of the starter but when I got my cheapie Halfords battery (fitted last winter) checked by two different guys both said with a disappointed look that he battery was fine, but one cheered up when he heard the starter and said 'Ahhh, but that doesn't sound too healthy €€€€€'.

'F**k it' I said, the one thing you can't have with an auto is a bad starter (believe me I learned this the hard way resulting in a 3.9 RRC stuck on top of a mountain for a few weeks) and ordered one on the spot (€280) which he had the following day. Now, not knowing which came first (assuming that the hot start prob had killed the starter), chicken or egg, the same day I orderd a timed relay off ebay to do the 'Fix'.

New starter came and was fitted the following night.

Guess what, no more hot start problem.

The relay arrived last week but I haven't fitted it yet.:doh:

So heres the thing, its never been exactly pinpointed but the hot start problem is universally attributed to wear in the diesel pump. It normally starts to affect the M51 engine around 80-90,000 miles.

So whats the life expectancy of a starter motor? At what stage does its performance reduce the cranking speed and hence the pump pressure available from the pump. I know the fuel map, timing and lack of glow plugs doesn't help but is the viscosity of diesel that different between 10deg and 40?

All I know is that my P38 was exhibiting all the classic symptoms of a hot start problem and one new starter later its not.

Now the 'Fix' will still cure the symptom but is it covering up an impending failure that will leave you stuck in a car park somewhere anyway?

spudh, just a reply on that, i d love 2 have tried t old starter with t new battery, had a little trouble with mine, a battery issue was good 2 start in t morn but a 6 min drain and it was finished, even though it checked out good with all t battery testers, anyhow i bought a 110 amp varta just 2 be sure, same test 11 min later, and started no prob. a cousin had one, loads of starting probs even with a 1 year old battery, and i mean loads, would start when cold but lazy, hot starts be a fingers crossed job, so i told him what 2 do, so he bought a new 110 amp varta, problem solved, t p38 likes its power.

i think it should be investigated if anyone has the issue, or like spud, has an old starter. it might be worth putting an old battery (1 off yer mates) see if the issue recurrs,

if its simply a starter or battery thats needed then theres loads of people who could benfit from that knowledge!

I never changed the battery this time. The only thing different is the starter. Its audibly turning over a lot faster with the new starter.

I couldn't keep the starter as it was a part exchange.

I've no doubt that the halfords battery isn't great, I will change it, its just gone down the pecking order.

P38's must have a very good battery to make sure the whole car works as it should.

I learnt this last year shortly after getting my car. I had a dead cell and did not know. The car was starting badly and other elecy things were playing up. A correct battery fitted, and she was fine.

The exact same battery is also fitted in a MAN truck, but its 1/2 the price!! has saved me a LOT of £££ over the years, and if you get it from a dealer, it had a 3 year ££ back warranty

Low cranking revs is a definate hot or cold start problem on diesels. In the last ten years both my tractor and excavator have been cured of starting problems by changing the starter motor. On the tractor starter motor the bearings were so shagged that the armature was rubbing on the field cores.