Toyota D4d - common fault and how to fix.

[TimberCutterDartmoor]

Spent a few hours today in the top end of my D4d engine. Injector seals are a known issue on earlier models so if yours is watch out for this!

 

Initial tell-tale is slow oil pressure rise caused by solids in the pickup screen in the sump; said solids and sludge are from combustion gases leaking directly past the injector seals in the head into the rocker cover where the cams and tappets are - not good; fouls the oil quickly with resultant issue at the bottom.

 

I pullled one injector at a time and had a bit of fun getting the old copper seals out; worked backwards from #4 - all were clean enough, but #1 oh my - see picture - horrendous! Gases had also cooked the o-ring so it was a real mess in there - look at the state of the whole cam box as a result - grim.

 

Copper seal in #1 was very eroded and carbonised; worse still it's as eccentric as it looks in the picture; the hole is well off centre; whether it's eroded that way or was a faulty part from new, who knows but shocking either way.

 

Supposedly sensitive and fragile injectors nonetheless had a wipe down and tip clean; #1 I was a bit more savage with!

 

Clean the injector wells out good (carb cleaner and compressed air), replace with upgraded silver seals and reassemble.

 

Sump off, inspect pump pickup screen, flush and O&F change tommorow...

[mendiplogs]

Spent a few hours today in the top end of my D4d engine. Injector seals are a known issue on earlier models so if yours is watch out for this!

 

Initial tell-tale is slow oil pressure rise caused by solids in the pickup screen in the sump; said solids and sludge are from combustion gases leaking directly past the injector seals in the head into the rocker cover where the cams and tappets are - not good; fouls the oil quickly with resultant issue at the bottom.

 

I pullled one injector at a time and had a bit of fun getting the old copper seals out; worked backwards from #4 - all were clean enough, but #1 oh my - see picture - horrendous! Gases had also cooked the o-ring so it was a real mess in there - look at the state of the whole cam box as a result - grim.

 

Copper seal in #1 was very eroded and carbonised; worse still it's as eccentric as it looks in the picture; the hole is well off centre; whether it's eroded that way or was a faulty part from new, who knows but shocking either way.

 

Supposedly sensitive and fragile injectors nonetheless had a wipe down and tip clean; #1 I was a bit more savage with!

 

Clean the injector wells out good (carb cleaner and compressed air), replace with upgraded silver seals and reassemble.

 

Sump off, inspect pump pickup screen, flush and O&F change tommorow...

 

HI JON DO THE RIGHT THING buy land rover thanks jon

[ballibeg]

That's good work. In response to symptoms or purely preventative?

[TimberCutterDartmoor]

That's good work. In response to symptoms or purely preventative?

 

Not preventative - look at the injector!

 

Actually no symptoms to the layman but mild knock made me look deeper; remove oil filler cap when idling - you can hear the hiss-hiss-hiss if the seal has gone - nearly always #1 injector (the hottest end) which is adj to the filler cap and smell exhaust in the rocker cover; only smell from there should be crankcase oil fume, not diesel exhaust! Had those symptoms so parked her up and ordered the seals (£16.99 from Toyota). Injectors are probably a bit worn too but I'm not going down that route as it aint cheap and you have to match to the ecu. I shall put some RL85plus through the tank and reduce O/C interval accordingly.

 

Oh and another thing; do yourself and your diesel (any diesel!) a favour; drop the recommended 5W30 oil and put in 5W40 or even 50; reduces blow-by considerably.

Edited April 16, 2015 by TimberCutterDartmoor

[ballibeg]

Didn't ask that well did I!

 

So there were symptoms caused by the injector that caused you to go in rather than running fine but with an injector like that.

 

As a trafic driver I know the struggle getting them out can be...... Seems one of yours self lubricating!!!

[TimberCutterDartmoor]

HI JON DO THE RIGHT THING buy land rover thanks jon

 

Thanks but no thanks Jon.

[mendiplogs]

Thanks but no thanks Jon.

 

HI JON SORRY ABOUT THAT they do look loads of money mate thanks jon

[TimberCutterDartmoor]

Didn't ask that well did I!

 

So there were symptoms caused by the injector that caused you to go in rather than running fine but with an injector like that.

 

As a trafic driver I know the struggle getting them out can be...... Seems one of yours self lubricating!!!

 

It appeared to run fine but I heard a particular "knock" that made me do a bit of research; soon found that the noise under the oil cap said it all - seals gone and explained poor oil pressure rise at startup.

[TimberCutterDartmoor]

HI JON SORRY ABOUT THAT they do look loads of money mate thanks jon

 

I don't like Land Rovers Jon that's all, no apology required mate. I admit they have distinct advantages, but I'd rather have a 79LC to fulfill and exceed those needs if I had them.

[TreeswingerPerth]

100% agree with the oil issue , I had the same problems with the seals and oil pickup .

I'm now running mine on Mobil 1 extended life oil 10/60 , much better oil pressure and the whole engine is quieter and smooother .