New member with a new bunny

raab · Post by **raab** » Thu Dec 03, 2009 9:44 pm

Hello all. I have owned many a diesel Mercedes but just recently purchased my first diesel Volkswagen. Before going into my issues I would like to say I have been reading the board extensively since Tuesday and although there is a plethora of information here I would appreciate some opinions on this specific scenario. The car in question is a 1979 Rabbit.

I went to look at the car this past Sunday in Tacoma, WA. The seller stated that it had had new rings, new main bearings, new rod bearings and a rebuilt head. No records of the work being done. Rebuilt injection pump, also no records, but it looks brand new. The car was cold when I arrived. It billowed white smoke on startup but it was completely a half mile into test drive. I bought the car and drove it the 250-ish miles back to Portland without any mechanical problems.

I have been driving it short distances the past few days sorting out rattles and taking care of dew, dmv, new tires, etc. No problems until yesterday. Out of nowhere (as far as i can tell) i started losing power in little blips like I was running out of gas. Drove the car another mile, stopped, added 2 gallons from a can I was carrying. Continued with same issue. Continued to drive the car for a few more errands. Small amounts of blue smoke, struggle to get the car to 55 (I know the car is slow, this is beyond that). I begin to notice strange metallic noises that i later find to be the timing belt tension pulley.

Replaced the pulley this morning. Locked injection pump with the pin, clamped the timing belt to the cam gear so it couldn't move, I am 99% sure my timing is still correct. The car smokes like hell, both white and blue. Will not idle. Starts easily, runs for a few seconds and dies. I questioned the fuel supply/return so i ran the car off of a separate fuel tank with the same results. Took it on a small test drive. No power, car dies if I try to let it idle, white/blue smoke like crazy at idle.

Pardon me for writing a novel. I would appreciate any tips. Symptoms sound like fuel supply/return from what I have read but I think I have cleared that? Blown head gasket? Would you notice the moment your head gasket blew or can it occur slowly?

Any guidance is very much appreciated. I love this car! Can't wait to get it back on the road.

82vdub · Post by **82vdub** » Thu Dec 03, 2009 10:50 pm

Welcome to the forum. One item you may want to pay particular attention to is if the motor was rebuilt with head studs, or head bolts. Head bolts are a problem on 1.5's. I'm assuming you have the 1.5 and not a newer 1.6.

Typically bluish smoke means unburned fuel, from retarded timing or low compression. To check for a bad head gasket, when the engine is stone cold, start it up and if you have pressure and bubbles/steam forming in the overflow jug, compression gasses are getting into the coolant. In any case, a compression test will tell you a lot on the internal condition of what you purchased.

The slight metallic sound could have been the valves starting to kiss the pistons. The pully on the camshaft could have started to slip, or the key is sheared or missing on the crank cogged pully too. Double check. And, set the timing up according to the Bentley manual, which is to loosen the cam timing gear and adjust the tensioner. If you didn't do that, you may have redone the tensioner and left the timing (to the cam and pistons) in question. You can time the injector pump (IP) by the dial gauge, but you may want to advance the IP a bit to see if the blue smoke goes away. Don't time the IP with the cold start lever pulled out, and make sure you rotate the engine a couple complete revolutions by wrench after messing with the timing before you use the key to turn the motor over.

The other issue is fuel starvation. Could be the fuel filter is plugged (if you haven't changed that since you owned it, do it!) or the screen in the tank is plugged. You can put a vacuum gauge on the inlet fuel line and check for vacuum. That will tell you if you have a blockage somewhere. Also loose fittings or bad lines can let air in, which will pretty much render the throttle useless until the fuel solidifies, after the engine dies. Look a little closer and post what you find.

raab · Post by **raab** » Thu Dec 03, 2009 11:48 pm

Bingo. I failed to set the timing correctly.

Many of the directions in the Bentley say 'If the timing belt did not break proceed in this fashion...' But it does not say what to do if the timing belt did break. Although mine id not break, at this point is off by enough to proceed as if the timing was off, right? I think I will go back to square one and replace the timing belt this time around.

If I understand correctly, I can follow the Bentley directions but given my timing is off I will need to re-sync the cam and drive shaft and then proceed as normal...

wolf_walker · Post by **wolf_walker** » Fri Dec 04, 2009 12:02 am

Buy a cam locking tool, or a 3" door hinge from lowes and massage it to fit.
The newer, early 90's 2L gasser valve cover gasket is one piece rubber and makes life easier than the old cork one, either find non-shouldered valve cover mount studs to go with it or buy some bolts from lowes. Allen heads look nice. An adjustable crescent on a cam lobe will hold it when you tighten the nut on the pulley, don't be shy with it. Unless the 1.5 differs, and I'm pretty sure it does not, there is no key there for the cam pulley even though there is a keyway on the cam, such that you can adjust things easier.
Don't let it slip later on, bad mojo. Book timing isn't always best on the pump, I'd use the gauge if you have it, make some reference marks, and fiddle with it some. And don't over tighten the belt, it turns slow enough and is deeply cogged enough it really don't need to be too tight, bad mojo for the water pump and pump bushings when it is.

I'm an old Mercedes guy too, though I have only a 73 W114 gasser at the moment, go figure.

Post by **Fatmobile** » Fri Dec 04, 2009 12:33 am

A novel isn't so bad when you space it out. I give up when reading a big blob of words.

The 10mm/13mm wrench in the spare tire tool kit works great to lock the cam too.
Break the cam bolt loose before you remove the belt,.. don't use the cam locking tool to hold the cam while you break the bolt loose, cams have been broken that way.

Injection pump nut should be broken loose with the belt still there to hold it too,.. if you are going to remove the pump for a reseal or install a new passenger side motor mount.

Good time to check the intermediate shaft bearings, by pulling it out while you are changing the I-shaft seal and o-ring. I put a deep socket 13mm on the seal carrier bolt, through the hole in the I-shaft pully, to hold that pully while breaking the bolt loose.

raab · Post by **raab** » Fri Dec 04, 2009 12:51 am

Thank you all for your help.

I have read and re-read the Bentley 20 times over now, as well as the posts here, and I can not for the life of me understand why you would lock the cam and then loosen cam timing gear?

By preventing the cam gear and the pump gear from turning, and preventing the belt from skipping any teeth, wouldn't I have maintained perfect timing?

Quantum-man · Post by **Quantum-man** » Fri Dec 04, 2009 3:30 am

raab wrote:Thank you all for your help.

I have read and re-read the Bentley 20 times over now, as well as the posts here, and I can not for the life of me understand why you would lock the cam and then loosen cam timing gear?

By preventing the cam gear and the pump gear from turning, and preventing the belt from skipping any teeth, wouldn't I have maintained perfect timing?

I personally would not lock the cam with the locking plate... before,,, applying a 19mm/3/4" spanner on the cam bolt and a sharp tap with a hammer to loosen the bolt first.

82vdub · Post by **82vdub** » Fri Dec 04, 2009 9:49 am

raab wrote:By preventing the cam gear and the pump gear from turning, and preventing the belt from skipping any teeth, wouldn't I have maintained perfect timing?

Yes, you would have maintained perfect timing as to how it was timed before you disassembled it (or close enough to call it the same). Problem is, if it was incorrectly timed in the first place, you just did all the work to create the same problem all over.

You will definately want to loosen the cam sprocket and let the sprocket freewheel as you tension the timing belt with the cam lock in place, then snug up the cam sprocket bolt, remove cam locking plate, then final tighten the cam sprocket bolt. All that's done with the IP locking pin in place. Then, very importantly, rotate the engine at least two complete revolutions with a wrench on the crank bolt before using the key.

libbybapa · Post by **libbybapa** » Fri Dec 04, 2009 9:58 am

You can certainly check the cam and pump timing prior to loosening anything up. Be sure you have come up to TDC going only clockwise so that the belt is taut between crank, pump and cam in order to check the cam alignment. If the slot is perfectly aligned with the head at TDC, then there is no need to loosen the cam.

raab · Post by **raab** » Fri Dec 04, 2009 12:00 pm

does it matter if tension pulley is tensioned clockwise or counterclockwise?

libbybapa · Post by **libbybapa** » Fri Dec 04, 2009 2:26 pm

Yes. It is supposed to be rotated clockwise to give greater degrees of engagement on the cam sprocket.

raab · Post by **raab** » Fri Dec 04, 2009 3:31 pm

When I manually turn the engine over using the crank bolt I get a about 1/8 turn before hitting something, which to me sounds like piston/valve interference. So...

A) At how many degrees / belt teeth off time would you get this interference?

B) Would the car run (at all) if the timing was this far off and the pistons/valves were beating the hell out of each other?

This feels like a lot of contact, not a 'kiss'.

Thinking ahead: Anyone in the Pacific NW have a spare 1.6?

82vdub · Post by **82vdub** » Fri Dec 04, 2009 4:05 pm

raab wrote:When I manually turn the engine over using the crank bolt I get a about 1/8 turn before hitting something, which to me sounds like piston/valve interference. So...

Yep, that's likely what it is.

raab wrote:A) At how many degrees / belt teeth off time would you get this interference?

I don't know what the actual number is, but it doesn't have to be off by much for interference to take place.

raab wrote:B) Would the car run (at all) if the timing was this far off and the pistons/valves were beating the hell out of each other?

Yes, it will run with the pistons hitting the valves pretty hard. The harder the hit the shorter it will run, the softer the hit the longer it will last. The valves are straight up from the cylinder, so it's hitting the face of the valve, not at an angle. Less damage than when a valve's at an angle to the cylinder, but not good nonetheless. If you do a compression test and find you have good compression, it's probably ok.

raab · Post by **raab** » Fri Dec 04, 2009 6:36 pm

Ok I am approaching this all as a lost cause at this point. I drove the car for about 4 miles in its currently timed state yesterday.

I loosened the cam to alleviate the interference, turned the crank to TDC and then turned the cam to the appropriate position. All of this with the belt removed.

Now I need to check timing of the injection pump. Can I assume that one of the lock holes on injection pump timing gear will be correct timing? I have the gauge so will check with that but are these lock holes just for locking or are they intended to be a significant position?

wolf_walker · Post by **wolf_walker** » Fri Dec 04, 2009 6:47 pm

raab wrote:Ok I am approaching this all as a lost cause at this point. I drove the car for about 4 miles in its currently timed state yesterday.

I loosened the cam to alleviate the interference, turned the crank to TDC and then turned the cam to the appropriate position. All of this with the belt removed.

Now I need to check timing of the injection pump. Can I assume that one of the lock holes on injection pump timing gear will be correct timing? I have the gauge so will check with that but are these lock holes just for locking or are they intended to be a significant position?

There ought to be one hold in the pulley that you line up and the pin fits through it into a locking spot to hold it. If you look there should be(when it's lined up) a mark on the pump side of that pulley, there is also a mark on the bracket. This is sort of a loose timing position, line marks up, put lock pin in, put on belt with crank at TDC, cam gear loose, cam locked with both lobes on #1 straight up, once the belt is on and snugged up, tighten cam gear. Rotate, should be good. It ought to run timed like that, you can tweak by ear or with a gauge later.