Newby with d24 engine problem

[Fmark]

I am presently living in Victoria Beach, NS and have owned a 1984 VW LT 28D Camper for approx. 10 years approx 200,000 km before rebuild
Last year while travelling on a 10 day trip, my timing belt broke and destroyed the camshaft and damaged a number of valves.
After having it towed back home, the head was inspected and I decided to order a new cylinder head from Germany plus gaskets, new water pump, new belts new head bolts and the 6 injectors rebuilt with new parts.
A local mechanic (with a little assistance from me) put the engine back together and after doing the timing and bleeding the injectors the engine started and ran quieter and with more power for about 10 hours at highway speed. Then I heard a dramatic increase in sounds coming from the engine and accompanied by a significant reduction in power. Also, there was a noticeable increase in black / carbon smoke coming from the exhaust system especially when climbing hills. I was able to limp home with the machine.
Also, I had topped off coolant, done an oil change and had just replaced the air filter.
The mechanic is presently checking the following
Air filter and intake flow---OK
rechecking timing
checking compression of each cylinder
stethoscoped the rebuilt injectors---OK

ps--- there is a small amount of oil around the vacuum pump and there is a hole in the side of the pump where it appears that a plug has popped out and there is a small amount of gases/oil coming out of it.
I don't know if there is anything from this component that would affect/ cause the engine problems described

Can anyone give me a solution for this problem
Fmark

[ngoma]

Hello, welcome to the forum.

One of the failure modes of the vacuum pump is excessive noise (clackey) but the vac pump should not have any effect on power or smoke. The engine can run fine without it. In fact, one of my future plans is to remove it, cover with a block-off plate, and plumb in a suitable electric vac pump and reservoir.

Oil leak that looks like it is from the vac pump could be from the valve cover gasket, head gasket, or the vac pump-to-cylinder head sealing o-ring.

Can you post a photo of the missing plug?

It will take more iterations of troubleshooting to identify the problem area and arrive at a good solution.

Can you describe more clearly the "dramatic increase in sounds?" What kind of sounds?

Tell us about the mechanic. Well experienced in the D24? The crankshaft pulley bolt, camshaft timing, and IP timing are items that require specialized D24 knowledge and tools, not common on other diesel engines.

Verifying the IP timing will tell us much. Also have the turbo checked. Were you able to hear its whine or whistle before? Can you hear it now?

Your answers will determine the next steps...

[Fmark]

Originally Posted by ngoma

Hello, welcome to the forum.

One of the failure modes of the vacuum pump is excessive noise (clackey) but the vac pump should not have any effect on power or smoke. The engine can run fine without it. In fact, one of my future plans is to remove it, cover with a block-off plate, and plumb in a suitable electric vac pump and reservoir.

Oil leak that looks like it is from the vac pump could be from the valve cover gasket, head gasket, or the vac pump-to-cylinder head sealing o-ring.

Can you post a photo of the missing plug?

It will take more iterations of troubleshooting to identify the problem area and arrive at a good solution.

Can you describe more clearly the "dramatic increase in sounds?" What kind of sounds?

Tell us about the mechanic. Well experienced in the D24? The crankshaft pulley bolt, camshaft timing, and IP timing are items that require specialized D24 knowledge and tools, not common on other diesel engines.

Verifying the IP timing will tell us much. Also have the turbo checked. Were you able to hear its whine or whistle before? Can you hear it now?

Your answers will determine the next steps...

Thanks for the comments
The d24 does not have turbo
The mechanic is self taught (50's) with much experience on VW's. His experience is on 4 cyl diesels
He used the d24t.com website to get the timing procedures
This is his first experience with a six cylinder d24
Before start up after the rebuild he hand cranked the engine to make sure the new parts would not self destruct
It was necessary to crack the injectors one at a time while cranking to get fuel to the injectors
The engine then started and ran quiet, smooth and with better power than before rebuild and ran that way for about 10 hours. We were out touring on day 2---3hrs running speed 70 km/hr when it instantly got louder
My guess is ---noisier in the top end valves/camshaft, etc. generally louder overall---not enough lubrication possibly???
I will visit the mechanic today and take a picture of the vac pump
I had the fuel tank cleaned out about 8yrs ago
I changed the fuel filters(2) about 4000km ago and installed a fuel vacuum guage
The guage was not calibrated but in relative terms from past use the filters are looking like they are in good shape
I was thinking about replacing them just so we could eliminate them as a possible reason for the power loss
I am not very good at computers and am learning how to communicate on the site out of necessity to solve my present problem
Fmark

[ngoma]

OK. We await the results of the timing check.

[v8volvo]

Sure does sound like slipped injection timing. As ngoma said the timing check will provide the critical info you need.

Even just a rough visual check of injection pump timing using the external timing marks on the IP and flywheel might give you a hint as to whether your issue is in this area.