questions for 300tdi gurus

[piper109]

I am learning to live with a 300tdi engine in my 99 Disco D1.

It has about 165 k miles but was supposedly repaired about 15k miles ago following an overheating issue. It was rebored to 1st oversize and a new AMC cylinder head was fitted. I recently drove about 600 miles with a lot of motorway and mountain driving. Temps in the 80s and 90s F. No oil or water used.

Questions:

1 When I start it from cold,(without using glowplugs) it starts instantly but wont rev cleanly. When driving off it smokes badly for about 100yds then it stops smoking and everything is fine. It this the infamous puff of smoke when starting? To me its more like a cloud. If I use the plugs will this be prevented?

2 Before I fitted this engine, I replaced the glow plugs and put in new ones. Some of the old ones were wet with either oil or fuel, oil I think. Would this indicate the valve seals are bad? Can they be replaced without taking the cyl head off?

3 Cruising on the motorway at 75mph+ with the aircon working, on long hills I see the temp gauge climbing a little. It goes from just below the horizontal mark where it usually stays, to about 10 degrees above horizontal. I slow down to let the temps drop back down.

Is this normal? Does it indicate the cooling system needs to be flushed better? The rad is quite new but is there a bigger model I can fit? Does it indicate head gasket leakage?

4 Is there a way to make the turbo spool up earlier? It smokes heavily when climbing steep hills much below about 1900rpm. The pump has been adjusted to rotate the diaphragm about 90 degrees only.

Thanks,

Steve in South Carolina

[sutty_32]

Hi there,

I was leaving this post to see if a bigger boy would come along and give you better answers, but hopefully I'll i've give some useful help!

1. Sounds like you'd expect to me, should be reduced a bit with using the glow plugs. Some smoke more than others but as long as it clears up quickly doesn't sound like much is too wrong.

2.My glow plugs had oil too, 3 of the 4 were soaked! I fully re-built my engine for a number of reasons, replacing the valve stem oil seal, but I replaced a lot of stuff so it might not have been this that fixed it though it does make sense. It may be possible to do this without taking the head off. You would have to take the rocker arm and valve collet/springs off. I have heard it is possible by putting the piston to tdc then compressing it so the valve rests against the piston. It's not much more effort to take the head off at this point, just the head bolts and exhaust/inlet manifold and you can replace the head gasket then.

3. Sounds like the engine is running fine but does sound like the cooling system could do with a flush, doesn't harm anything to do it! They are quite bad for blocking up the rad, how new is the rad? Don't think there is a bigger one you can fit, they are oversized anyway for this country. Mine has around 2/3rds of the fins missing and doesn't overheat! Not sure if this indicated a head gasket issue, any water in oil or oil in water?

4. You can adjust the low speed fuelling (i.e. before the turbo spools). Its the torques bit screw on the fuel pump, there are guides on this forum I think. This should increase fuelling low down and make the turbo spool quicker. Might be worth flushing the intercooler too. My turbo spools up about 1400rpm.

Hope this helps!

[Tim Turner]

Hi,

What is the ambient temperature like to be able to start without glowplugs?

You have not said what transmission you have. Automatics have electronic diesel control and turbo pressure is computer controlled. My auto pulls awful until it starts to warm through, and when glowplugs are failing is even worse and smokes terrible. Also if it is auto then you need to remap the ecu to change fueling.

Tim

[piper109]

Hi,

What is the ambient temperature like to be able to start without glowplugs?

You have not said what transmission you have. Automatics have electronic diesel control and turbo pressure is computer controlled. My auto pulls awful until it starts to warm through, and when glowplugs are failing is even worse and smokes terrible. Also if it is auto then you need to remap the ecu to change fueling.

Tim

I am starting without glowplugs in temps about 60 F though later in the day its 80 or even 100. Even at 60 it starts instantaneously. I have now hooked up the glowplug circuit all except the dash light but I can hear the relay time out. I only wait for it when the engine is cold. The smoking seems to have mysteriously stopped. Perhaps the valve seals have softened up and started working again. Gearbox is 5 sp R380. I just took out the auto with the V8.

I have flushed the radiator now and added some Redline "water wetter" which is supposed to improve radiator efficiency. I will be doing about a 200 mile trip later today so I will see how it does. I believe the rad is fairly new. It may be a Britpart or something and be smaller than the factory one.

Thanks for replying to my post.

Steve

[BogMonster]

A healthy 300Tdi will start without glowplugs nearly down to about freezing temp, it just takes a few more turns of the engine but with a decent battery is rarely a problem. Age and a bit of wear reduces the compression so an older one will need the plugs more.