Vacuum Pump Leak at Head

[ngoma]

Leaks pretty good where the vac pump connects to the cylinder head. 13mm Connecting nuts are tight. Did some searching and am suspecting it will need a new o-ring seal. Does anybody have a source? Looks like I will need to rotate the engine to TDC to reinstall the vac pump, to allow the plunger rod to return.

V8volvo, I may have bought one of the cars you wrote about earlier. Was one of them the Marble car?

[IceV_760]

Its not necessary to turn it to TDC to fit pump back.
Its just a "bit" tighter to place when nose-axles peak is on wrong place on wrong time, and if you feel so just randomly turn engine. Roughly 270*deg. out of 360*deg. you should be able to place it easily.

[Jason]

I checked our listings and I don't see it unless you get the gasket set. You could try tasca.

Jason

[ngoma]

Thanks for the speedy replies. If it is indeed an o-ring, I could probably bring it to a local warehouse (Tacoma Screw?) and have them measure/ match up a replacement.

[v8volvo]

The part is an oval-shaped O-ring. Available through Volvo, it costs about $7. Or you can take the old seal out and bring it to an auto parts store and get any round O-ring that is the same size. A round one will work, but it is more difficult to install than the proper oval one from Volvo, since it will want to jump out of the recess where it sits when you turn the pump vertical while installing it. Use a bit of light grease (assembly lube or Vaseline are ideal) to hold it in place as you install and it will work fine. I use the genuine Volvo product since it only costs a few bucks more and I know it's right, but I'm a perfectionist and it's not really necessary...

Tacoma Screw would probably have something that would work, just make sure it is an automotive or marine product because it needs to be able to stand up to oil and high temps. Many kinds of rubber will break down when exposed to those factors.

A tip: do NOT use any RTV or other sealant when reinstalling the vac pump. If the O-ring is good, sealant is completely unnecessary and all it will do is make a mess. If there is already some on there, as there usually is from some past mechanic being an idiot, then clean it off and install it dry with just the O-ring. You don't want bits of squeezed-out sealant getting down that oil drain hole in the head and ending up somewhere inside the engine, blocking oil flow.

It is easiest to install when the engine is at #1 TDC since you don't have to fight spring pressure to get it back in. Also try to ensure the plunger gets installed back in the same way it was before, to prevent excessive wear of the cam lobe that drives it. Easy to find #1 TDC by looking at the pulley on the injection pump and roughly matching the notch in its rear flange up with the notch on the pump bracket. It doesn't have to be exact, just getting it close will make the job much easier.

ngoma I assume you are located in the Puget Sound area... what is the Marble car? You'll have to jog my memory...

[v8volvo]

If you get the complete cylinder head gasket set, for instance the Reinz one that IMC sells, it does come with the seal for the vac pump, but it uses a round O-ring, not the oval OEM-style one. Not a big deal but it is a slight difference.

[ngoma]

ngoma I assume you are located in the Puget Sound area... what is the Marble car? You'll have to jog my memory...
Last (2) owners name were Marble, the father (Lopez Island) passed it along to his son (W. Seattle). Anyway, it's sky blue, now has 173,xxx miles, was thinking it was the 157,xxx car you were describing for sale last June?

Trying to sort out the misc. issues:
Oil leaking from vacuum pump.
Leaky injector jumper hose #3-4.
Worn PS pump mount bushings.
Shakes (misses?) at idle and off-idle.
Excessive smoke at WOT/hi revs.
Failing u-joint that growls on windup.

I already fixed the starting problem by replacing GPs #1, 2, and 3.

And brought the coolant temp gauge to life by plugging it in to the correct temp sensor next the GP #1, and moving the GP controller brown temp sensor wire to its correct sensor at the rear of the head, below the cam sprocket. Will need to run new wire for the deteriorated coolant sensor wire, and also the oil pressure sensor wire.

I feel I can get a handle on things if I can find a good supplier; I like to support local-- any place you recommend here in Seattle?

[Jason]

Might try running some quality injector cleaner through it to help with the missing, assuming they aren't leaking. I ran the BG 244 and it made a very noticable difference. With the miles, it may just be time for rebuilt injectors though. Check your boost to see what its making for the high rpm smoke. The injection pump may have been adjusted possibly incorectly as well.

Jason

[ngoma]

Jason you may be onto something. Maint. records show no evidence of injector rebuild or replacement, 173,xxx miles is plenty for orig. injectors. Should be fun to pull them out. Car came with a clean reman injector (tag states 155 Bar) and heat shield in a Volvo Remanufactured Part box in the trunk, along w/ some green books, orig. manuals, service receipts, etc. and 5 fresh Mahle oc105 oil filters.

I'll see if the local Bosch shop has heat shields, and also a repair kit for my old Bosch pop tester. The gauge shutoff valve drips out the shaft and the pump is tired.

Cleaned/matched injectors might help the idle miss and smoke.

Don't have a way to check the boost but the fuel delivery screw has been tampered with-- tamper seal is gone, and the yellow paint is chipped away from the screw and locknut. Feeling I had nothing to lose, I have turned this screw out 1/4 turn which seems to have cut down some of the excessive smoke, I don't know if this has affected the timing. Experimentation cut short by a progressively worsening injector return jumper line leak.

The previous owners had tried to maintain the car well. They spent plenty of $$$ at the shops, but I think some of these shops didn't fully understand the quirks of the d24t and so unknowingly sabotaged it to some extent.

V8volvo, if you are available for a consult I would like to bring the car by to get your opinions.

[Jason]

My car has right around 170k miles and the BG really made a difference. I was going to buy rebuilt injectors but once I ran the BG through it, and have just been running the crap out of it in general, it has really smoothed out... Enough to where I'm leaving them in.

The full power screw wont affect timing, you also may want to look at the depth of the allen head screw and jamb nut on the top of the afc housing on top of the pump. If its been bottomed out, loosen the jamb nut and unscrew the allen head bolt untill it stops, then snug the jamb nut again. With the correct injection pump settings, the factory level of boost should totally clean up the exhaust under full throttle and full boost. I would keep turning the full power screw out 1/4 or 1/2 turn at a time, you will probably have to adjust your idle speed up a little to compensate. I would recomend driving it between adjustments, as you reduce the fuel quantity obviously you are going to loose power, you may find that putting up with a little smoke may be worth it for the extra power to get out in traffic!

Jason

[v8volvo]

I still have the 157k car, its motor is pretty far gone but I'll be installing my good spare one at some point this winter, whenever that elusive free weekend turns up... Is yours the one that was advertised on CL for the past several weeks, down in Tacoma IIRC a light blue or silver sedan with blue interior?

Regarding the engine running problems you described: Could be injectors, or they could at least be a contributing factor, but there are several other possibilities as well. One is valves -- they probably have not been adjusted in ages and may be out of spec. Misadjusted valves can also contribute towards smoke, poor starting/running, and low power. They are easy enough to check, just need a set of angled feeler gauges. If they need adjustment, that's more of a job, requiring special tools and a set of shim discs of varying thicknesses. I have all that stuff so can help out if you get to that point with it.

Make sure your glowplugs are a matched set. If you don't know what kind are in the rear 3 holes, then put in the same type you installed in the front three so they can be ruled out as a possible factor. Mismatched brands/types of glowplugs can cause all kinds of running issues, including major engine loping due to uneven compression from unequal-sized tips taking up varying amounts of volume in the combustion chamber and causing uneven engine compression. Ask me how I know. ;)

I have had OK results with injector cleaner products in some cases -- Diesel Purge is a good one, made by Liqui Moly -- but at the end of the day injectors don't wear out just by becoming dirty. The physical metal parts themselves wear down, and running a cleaning product won't fix that. After 170k, they should be rebuilt. If you have a pop tester, then you will be able to make sure they are all matched properly and have a good spray pattern. That will help the engine run better in every way. The only time I have seen injector cleaner really help is when someone has done something dumb to their engine, such as running unfiltered and unheated veggie oil in November like happened to the poor Mercedes that got towed in a couple weeks ago. Don't do that. :rolleyes: If you do, BG or diesel purge will help clean up the mess, but my guess is that in your case they are just plain worn out.

Finally, here is the big one: timing. You are right that most shops had no idea what they were doing when they worked on D24T engines. Replacing a timing belt on a D24T is not a horrible job but you have to take some extra steps to make sure it gets timed right. Most shops don't take those steps -- they just slip a new belt on and don't worry about it. That causes the engine to start and run much worse. Timing would be the first thing I would check. If you don't have the tools or know-how to do it, let me know and I'll find a way to help out.

If you get your timing, glowplugs, and injectors sorted out, and assuming the engine compression is still solid, then I think you'll be much happier with the way it runs. I'm happy to give it a look-over some point; shoot me a message about setting up a time. What part of town are you in?

Local parts sources around here are tough -- at the shop we can get parts through IMC which has a good selection, other than that there's Ravenna Volvo, which I don't mind supporting, and Abe at MBMW Parts is a good guy too. There's Bow Wow in Lynnwood for VW parts, but they are not great on Volvo stuff. For Volvo body/chassis/interior items Northern European in Ballard has everything but they are not cheap and have almost no D24T stuff.

Don't forget to run sustainable biodiesel in it -- Dr. Dan's in Ballard is the place to get it. Better for the car and for the environment. :cool:

[ngoma]

Yes that's the car.

Injectors were last checked May 2007 143,000 miles, apparently got the OK.

Valve adjustment: Records show head gasket replaced May 2008 158,xxx miles. Repair invoice calls out $475 sublet "Machine Shop Rebuild Cylinder Head," hopefully this included valve adjust. New HG looks to be a 3-notch fiber type, invoice shows new bolts. Retorqued 1200 miles later. Is it worthwhile checking the valves again, approx. 15,000 miles later? Can the VC gasket be reused? Previous valve adjusts: May 2007, 140,000 miles, Nov 2003, 85,xxx miles, Oct 2006 65,000 miles, Jan. 1989 33,xxx miles, Mar. 1987, 17,xxx miles.

GPs are a matched set, as far as brand/pn: Bosch 0250 201 032, but different ages. #1,2,3 are brand new, #5,6 replaced May 2000, 65,xxx miles. GP #4 (along w/ #1,2,3) was replaced Nov 1997, 58,xxx miles. Given that #4 currently tests OK, could it still have eroded to the point it is affecting compression?

Compression tested recently June 2009, 170,xxx miles.
385 400 455 380 400 395, might be worthwhile pulling GP #4 just to see if there is correlation there.

Found a local source for the vac pump mount o-ring, ($2, seems reasonable enough, we'll see if it's the correct shape) Larrys Volvo, pass right by it to/from my daughter's school.

[v8volvo]

Yep, Larry's is a good shop. They are the only other shop in town besides ours that has the correct tools and know-how to work on diesel Volvos. I will be interested to know if the O-ring you get is the right kind -- let me know. Those guys have been the only show in town as far as Volvo diesels for a long time so they may know some things that the rest of us don't in terms of getting parts, etc.

If the valves were done when the head was at the machine shop (which they should have been), then they are probably OK but it doesn't hurt to check them. If your valve cover gasket is the 1-piece rubber type it can be reused forever. If you have the old 4-piece cork kind it's worth upgrading to the rubber type anyway since it doesn't leak.

Glow plugs don't erode, so if yours all match then that's not your issue. The compression readings are on the low side, though. My '86 wagon with 271k was right in the same ballpark as yours, maybe a tad higher (I think there was only one cylinder that was in the 300s). My '83 764 had all 6 above 500psi when I checked it a couple weeks ago. The compression could account for part of the running issues you're seeing. If you don't already have synthetic oil in it, you might try running some fairly thin-grade syn (5W30) for a while and see if it helps free things up. If it has been run on dino oil its whole life the rings are probably pretty gummed. Lubro Moly makes a 5W40 semi-syn "Anti-Friction" oil that might also be worth a try. It has some kind of molybdenum or other kind of special substance in it that gives it a sort of silvery appearance right out of the bottle, kind of like it has anti-seize mixed in with it. Looks scary but it had a positive effect on an '84 244 Diesel with weak compression that now runs strong, so might help yours out too.

Sounds like the car has really been looked after. It's always nice to get a fat stack of receipts that show someone has cared about it. Who has been doing the work on it up to now?

[ngoma]

O-ring is thin and oval-shaped.

Do you check compression cold or hot?

Have a few invoices from '90s-- Jim Fisher Volvo of Portland OR. 2000 to mid 2008 was Larrys Independent. Last two invoices Summer 2009 were Louis Foreign Car Repair. This was who did the recent comp test and worked on the GP system. Oil changes since 2003 were done by previous owner, usually 2-3000 miles, since 2006 he used a blend of synthetic/dino.

[Jason]

You could also try BG 109 I think is the PN. Its supposed to dissolve carbon and gum build up and free up rings. May be something to think about. The compression readings are pretty up and down across the board.

Jason

[ngoma]

Took advantage of some good weather and installed the vacuum pump o-ring. It was leaking because there was no o-ring in there! Area now looks clean after a quick roadtest. Also the engine seems to idle smoother, although quite a bit of white smoke at cold startup and also if just let idle several minutes after cold startup. Warms up quickly while driving. The GP system apparently does not have after glow, is this true?

[Jason]

Yes once it goes off thats it. There isn't a timed on and off like the newer TDIs and whatnot.

Jason

[v8volvo]

Yep, it only lights them up before and during cranking, then for about 2-3 seconds after it starts, but not more than that. I have one aftermarket glow plug relay that does run them for longer, and runs them when the engine is hot too. It aids starting on tired engines. However, I prefer to have the plugs run less if possible, assuming the engine is in OK shape, so I took it off (my compression is good).

Larry's is a good shop and they know how to care for diesels. I would be reassured to see receipts from them -- the car was in good hands.

Compression can be done cold or hot, should not make a huge difference as long as valves are in proper adjustment. However, it is good to have at least run the engine somewhat recently, so that the rings are lubricated and achieving correct seal, etc.