Thread: DISCO 300TDI REBUILT INTERMITTENT STARTING ... ANY IDEAS?

Faulty fuel cut-off solenoid??? In a petrol powered car I would guess that a vapour lock could be the cause of your troubles. Haven't heard about that in a Diesel, though. Is the engine one with an electronic injection pump?

Does the engine turn over on the starter when hot or is it siezed, if so can you turn the crank by hand, socket and bar that is. You say you put in new rings, did you gap the rings to their bores, did you plastigage the big ends and mains, is the timing correct and have you checked the tappet clearances, Regards Frank.

If its not turning over then my guess is it's the starter motor. Probably the solenoid. There was a thread about it not long ago.

Does it crank over when hot?

Originally Posted by SAMUEL

Hello everyone. blew the head gasket and warped the head on my 97 300tdi. decided to do the big end bearings and rings (honed the bore) at the same time. brand new head, multi layered steel gasket, new garret turbo, new bosch injectors, new starter motor, new radiator,new battery ... etc etc.

problem is now the car will not start when it is hot from 85 deg to 74 deg. after it cools down it will start, or that is what seems to be happening.

i have checked all the electrics, battery, and earths.

is this a common problem after a rebuild??? its been 420 kms since we put it back together do i need to run it in still to bed in the rings or could there be a problem with the rings or bearings expanding/wrong size or compression?

any feed back would be very much appreciated. getting a bit over sitting for an hour waiting for my car to cool down before driving again!!

cheers

Sam, it is common courtesy when you ask a question on the forum to at least acknowledge that other forum users have taken the time to answer your questions.
So mate have you still got a problem, Regards Frank.

hi jojo, Tank and Disco Devil. thanks for your replays and sorry for the late follow up. I have been out of action but spent the day on the car and followed some of your suggestions.

Replaced the starter motor with a new one. still does not start when 84 deg? hot.if the car is just upto running temp 84 85 after 10 mins or so and i try to restart then sometimes it will fire up. the lover i drive it the less chance of it starting.

checked the fuel solenoid cot off and all the fuel injection system. all good.

isolated the earths and starter, solenoid with jumper leeds and retried with an auto electrician when hot but could not find the fault.

which leeds me to what frank commented on.... I did not check the ring spacing in the pistons and i did not plastic gage the big end bearings. This is about the last thing i can think of as to what could be the problem.

solution to this????
can i run it in over 1000kms or will it be causing damage??
do i need to pull the sump off and redo the big ends??

I started working on Land rovers just under a year ago, before that i could barely change a tyre and had no idea what a ratcheting spanner was ,so some friends have taken me under there wings and i have started to learn how to do mechanical work for myself(still with a lot of help).... biggest think i have learnt so far is to double check the manual with everything people say.... if i had have checked the above instead of following instructions maybe i would not be in this predicament.

Thank you again for all your advice... i hope to solve the problem and be back out on the trail ASAP

Samuel, you say the engine will not start when hot, does that mean that the engine turns over with the starter but does not start or does the starter try to turn the engine but either too slow or not at all. Can you turn the engine (when hot and won't start) over with a 27mm socket and bar on the crank snout bolt (easier from underneath), if you try this method disconnect the fuel solenoid wire on the IP first.
If you can rotate the engine manually (it would be a good idea to remove the glow plugs) without a great deal of effort and there is no binding or grabbing then it will not be the rings, how much did you hone out of the bore, did you use the original pistons, did you use standard or oversize rings. What size big end bearings did you put in, could you rotate the crank after you changed these bearings.
It is very hard to diagnose your problem from afar.
For instance if the starter is not turning the engine and you say you have a new starter and battery then the engine may be getting tight when it heats up, you could have rings that have too little clearance, same with bearings. Or if it is spinning over the fuel cut off solenoid could be inoperative when it gets hot. We need specific answers to all the questions to figure out what is wrong, so get back to us with the exact details, Regards Frank.

I have difficulties imagine that it should be your tolerances being too tight. In that case you would expect other symptoms as well, like unusual noises under load, reduced performance, detritus in the oil, etc. Having said that, any new or rebuilt engine can be somewhat tight in the early stages, but after running in this shouldn't be an issue. You have been driving yours for some distance, which should have improved the situation at least somewhat.
As Frank was asking, does the alternator turn at all when hot? What happens if you stop the engine when hot and immediately try to restart it?

Cheers Jojo and Frank, i will try both suggestions and post results friday night.

really appreciate the help!!!