Uneven engine operation.

[ngoma]

Originally Posted by Jimarilo

The air intake pipe that goes over the rocker cover has evidence of oil in it so suggests the engine is breathing heavy and at 165K I am thinking it is in need of a rebuild ......but is it worth it ??

Is that strong evidence for a rebuild? Where did you get this information?

What is your oil consumption?

What are the compression numbers?

With proper maintenance these engines can run strong for several thousand miles. Most early death examples are from botched maintenance practices (mainly insufficient tightening the crank pulley) causing catastrophic piston/valve interference.

[v8volvo]

Originally Posted by Jimarilo

Indeed, I am starting to think this engine is more trouble than it's worth. A nice merc 300 straight 6 would be a lot less trouble.

How so? You mean the OM603? They are far more expensive to maintain and get parts for and harder to work on. Cylinder heads fail all the time, flawed castings. Trap oxidizers always plugging, injection pump delivery valves constantly leaking. The D24T is a much better engine with far fewer inherent issues, speaking here from firsthand experience working on both day in and day out for years back when I was an employee in a professional shop.

Originally Posted by Jimarilo

Just changing the rocker cover gasket is a bleeding nightmare to change, especially if the nuts on the injector side are rusty and seized. It is probably just a matter of time before it starts leaking again on the exhaust side

14 nuts from my memory, maybe 16... Easy access with a regular 10mm socket on all of them, are we missing something here? The updated style rubber one piece gasket is not common for leaking and is even reusable. Once you get one of those in there, it's set for good.

Originally Posted by Jimarilo

I took the cambelt cover off to have a look at the belt as I am still in contemplation mode regarding the belt change, as I need so many specialist tools before attempting the replacement.

Total number of special tools is something on the order of a half dozen depending on what you are doing and needing exactly. Pretty standard for any diesel engine, it's the nature of the beast. You are absolutely correct that you do need the right tools.... but it's usually not a deal breaker. Very easy and inexpensive to improvise with slightly modified 2.5L 5cyl TDI cambelt tool set also, which is widely available for example on UK Ebay.

Originally Posted by Jimarilo

So with the slack on the adjusting pulley side, I slackened the adjuster bolt and let the adjuster take up any slack, which it did. What a difference that made, no stuttering when pulling away or when changing up the box and a little less lumpy on tick over.

Glad to hear the engine is running better , but am I reading you right that you made adjustments to cam and IP timing by altering belt tension, without using the tools to verify timing? It's always nice to know what timing setting you are running -- might be valuable to check it now. If changing the timing improved it this much, then there could still be further room for improvement, if for example the last fellow who did the belts failed to get timing adjusted correctly (perhaps hence your improvement from playing with timing). In other words you may still have not seen the best of it yet.

Originally Posted by Jimarilo

The air intake pipe that goes over the rocker cover has evidence of oil in it so suggests the engine is breathing heavy and at 165K I am thinking it is in need of a rebuild ......but is it worth it ??

Like on any other diesel engine, the crankcase vent tube will -- and should -- have some oil vapor in it. That's the reason it is there. Evidence of some oil presence in the CCV tube is NOT an indication of poor engine health by any means. Especially not on an engine that runs well, starts easily, and doesn't consume excessive amounts of oil. Those factors, and a compression test, are your real indicators of engine health. As ngoma already pointed out.

From everything I am hearing so far, you have a nice car and engine that could use a little attention but sounds like it's in sound basic condition and is most certainly worth the effort to keep it up.

Welcome to the board!

[BogfordGarage]

100% agree with v8volvo and Ngoma on this. As I understand from the owners forums you have been looking for a D24T for some time and now you have one it seems you're not overly impressed. The real questions to ask yourself is what were you expecting? And do you want to keep it?
I have to admit I'm not a mechanic by trade, this is a hobby for me and I'm assuming it is for you too. The D24 is a great engine when maintained correctly and the performance potential is there at a fraction of the price of modern diesels due to its simplicity.
I hope you choose to stick at it, the guys on here currently and in the past have shown passion and enthusiasm for something that most have forgotten and that is another reason I like this engine so much, the community is small but it's still there.
Hope you have happy spannering in the future

[Jimarilo]

I just wrote a post and pressed send and needed to log back in again then lost the post

Need to remember to copy the post before sending it .....doh !

Shorter version .........thanks for your replies and your optimism much appreciated. Obviously this engine is very different to other diesels that I have owned. It is not just a case of oil and filter changes and away you go. The car is in excellent condition, inside and out, a 1995 940S TD, so in the right hands would be a keeper for sure, of that there is no doubt. I love the way the car handles, it turns like my Peugeot 309 GLD, very quickly. It is a smooth ride and very reassuring, no knocks or bangs.

On a run down to Pitlochry yesterday ......2hrs each way, I could feel the engine holding back/missing intermittently, when on a constant throttle. When accelerating it seemed to pull ok. It hasn't done this before, even with a very dirty/blocked air filter. The engine still starts well on the cold start and when hot and idles ok, not as lumpy as before the slack was taken up in the cam belt. So as has been said, the valve timing and IP timing needs to be checked and adjusted before I get too despondent.

I need to find a dial gauge and cam lock plate. For changing the cam belt I need to make up the tool for the crank pulley .......is that a 27mm bolt ? Instead of using the tool to lock the crank pulley is it possible to lock the flywheel instead ?

Here is a useful vid, but lacks certain details
https://www.youtube.com/watch?v=Bp0UxiNM3SA

[Jimarilo]

Just ordered a dial gauge and camshaft locking plate kit, hopefully should fit

https://www.ebay.co.uk/itm/265142893171

[BogfordGarage]

Hi. The timing tools you bought look good hopefully they fit okay. The sudden missing and holding itself back is probably fuel related, perhaps if you have a fresh fuel filter it is a bad injector or maybe a sticky delivery valve on the pump, more likely an injector though. One inexpensive thing you could try before spending silly money is get a new fuel filter or empty your existing one if it's almost new, fill it with a diesel injector cleaner or Automatic transmission fluid (ATF) screw it back on. Run her up for a good while and that should clear any small dirt or debris if that's what's causing the problem. Be warned some people don't like using ATF to do this, in my experience it works better than any crap injector cleaner you can buy. Also do you have the green book service manual for this engine? It may help you out a lot.
Cheers
Tristan

[Jimarilo]

Hi, I have changed the filter and emptied the old one into a bucket and found some debris in the fuel. Running some cleaner through is a good idea. I agree on the injectors and currently bidding on an injection nozzle pop tester on ebay to refurbish the injectors

Once I have rounded up all the appropriate tools, parts and info I will get the timing and fuel system sorted. No green book as yet

Bought a spare deep 27mm impact socket to either fabricate the crankshaft tool or to use with a nobar break back torque wrench

Also picked up some domed head 6mm nuts and spring washers today for the rocker cover. The standard nuts allowed the thread above the nuts to rust through, snapping the top off two studs, as the shoulder below turns against the rocker cover. Luckily the stud left under the rocker cover is loose and easily taken out once the cover is removed. The studs can now be secured in the head with locktite. The domed nuts will protect the threads from now on

[BogfordGarage]

Ideal. Sounds like you're getting some bits sorted. There was a reasonably priced bound copy of the Green book on eBay I'll link it here https://www.ebay.co.uk/itm/354252013...mis&media=COPY
If you want a PDF copy instead of buying one I can get you one but it's for the D24 NA engine. All the procedures are pretty much the same it just doesn't include anything about the turbos and some of the figures for emissions and injector pop pressures etc will be different. I personally prefer having a hard copy as page turning is much easier.

I've just bought all the stuff for reconditioning my injectors, so keep us updated to see how yours are going.

That's a good idea about the rocker cover nuts. I've never had trouble with them seizing on mine but clearly it can happen. Being mechanical lifters on mine it comes off fairly regularly so I guess that's why it's not a problem.

[Jimarilo]

Many thanks for the link much appreciated, thats a 100% must have. So, there can be no excuses when armed with the correct data, will get the other half to purchase one tonight as it is her account ;-)

I just received the timing kit set and looks perfect and includes the camshaft plate and IP locking plug.

Ordered another rocker cover gasket ....this time the same as the original, a one piece rubber gasket

Just going to do a pre- mot check as it is due on the 22nd. I have a sympathetic local mot tester who loves old motors. He was well pleased with our 1989 Peugeot 309 GLD and went sailing through. Finger crossed