Belt Change Issue

I just finished up my cam belt change and I thought everything was fine. Car started up and ran so i put everything back together and took it for a ride. Car ran like crap. Rode around for a while thinking maybe the plugs were fouled but she still pops and backfires.
After further investigation it looks like the forward banks 5-8 exhaust cam is off by a tooth.
Either I screwed up or the belt jumped. Anyway is it possible to just loosen the tensioner and move the exhaust cam back in position without causing any damage or is it thme to seek professional help???

Mike

 

Whoops, it sounds like you didnt have it right to begin with mate.

I got caught once before when I did my apprenticeship.

Belt jumped two teeth after I started the engine.

Now..............after I fit cam belts I manually rotate the engine a few revoultions to make sure everything lines up and the cam belt still has the correct tension on it.

You can line it back up, loosen the tensioner and set it right mate. Shouldnt be any damage there.

 

I also just remembered, I had to repair a cam belt job for a friend the other day.

Well, a few weeks ago now. He did his own cam belt change, same issue here. The V6 had jumped a tooth. Car was missing/breaking down under load. He thought it was spark related and was stumped so he called me and left it with me.

I checked it out and found the ignition side of it was fine. Car was popping and back firing so I removed the cam covers and found cam belt was out one tooth. Pulled apart and fixed for him, all good now.

 

I took almost a month to do this job. After I set the belts I rotated the engine several times and all was well. A week later before I put the covers on I checked everything again and all was well. That is what has me concerned. I know I am old so I always recheck things. I am hoping I made a mistake and nothing else caused the belt to jump. One thing for all you 308 guys to look for is your a/c wire connector. Mine was rubbing on the timing belt. Had that wire broke it could wind up stuck between the belt and the gear causing failure for sure. Will let you know the results after I reset the belts next week.

Mike

 

did you change your tensioner?
One tooth is not going to do any harm, but you do get to do it over.

 

Did not change the tensioners but the tensioner bearings, water pump and a lot of hoses. Tensioners looked fine so cleaned and greased them and everything looked fine. Thankfully I removed the A/C compressor and did not put it back. Unfortunately I had a buyer for the car and now he is not sure. Will see what develops. Thanks for your responses.

Mike

 

When I do belts, I paint a bright orange stripe across the seal and the cam snout on all four cams. I do this after I have rotated the engine and set the tensioners. This allows me to verify the cams are where they should be after I put the covers back on. Removing the oil cap will allow you to see the alignment mark on the rear bank intake cam. This also helps confirm alignment with the paint on the cams

 

Good advice Pap,
I just did my 328 cam belts again. Once you have the belts on, DOUBLE CHECK, and DOUBLE CHECK again, then rotate the engine at least four times by hand, and check again.

Cheers,
Ross

 

Oh, that is interesting!!!

Are you sure you tightend everything in there mate?? Sounds like a tensioner may have come loose and caused the belt to loose tension and jump.

Good to hear Ross!

 

My saga continues. Took the cover off the 5-8 bank yesterday and looking at the marks I made, everything lines up. Looked at the 1-4 bank. Everything lines up. Now I am really confused!!. So I get out my timing lite and check the 1-4 bank. On the money 7 btc. Check
the 5-8 bank. Can't see the marks at all. The dizzy should be in the same place it was before so I ruled that out. Checked the marks again on the crank and flywheel thinking maybe the crank is out of time with the cams on the 5-8 bank and they look fine. Any ideas before I send this car to the scrapper!!!! I must have done something really,really stupid. No beers either.

Mike
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Mike,

When you said on the 5-8 bank "can't see the marks at all" does that mean when you are running your timing light, the advance marks aren't visible?

If that is what you mean, my guess is that the rotor shaft in the distributor turned while the distributor was out and is off a spline or two. The distributor (rotor) shaft on the 308 doesn't fit in just one way, as many distributors do- it can go in any spline orientation.

I had this precise thing happen to me recently. The distributor body is in the same orientation as before, but the rotor is off a bit. The engine will run, sort of, but the timing is far enough off on one bank that you won't be able to see the timing marks.

If we are on the right track, let me know and I'll explain how I then set up that one distributor statically to get back in the ballpark.

Good luck, Jeff

 

Mike

You did something wrong, and we don't know what it is yet. Can you tell us everything you have done from the beginning?

Remove the cam and timing belt covers
Remove distributors
Measure valve clearance
Remove cam shafts
Remove and change valve shims
etc

basically give us a view of what you have touched and done.

 

With the timing lite on the flywheel I cannot see the 5-8 mark that I marked with a red marker. I marked the 1-4 bank with a white marker which shows up clearly at 7 btc I did not pull the dizzys, did not remove the cam covers or cams. If you look at the pictures there is another set of yellow marks that the last person to change the belts did. They line up also. Very upset about this. I took my time and thought I did everything correct. There have been enough threads about this and I read every one. Cams were locked with my simple fixture, trans in gear so the crank won't move, belts went on fine. Confused to say the least.

Mike

 

Please go back a few steps.

1. Measure ignition wires and see what you have
2. Measure plug extenders.
3. Change plugs.
4. Do a compression check

How did you change your belts? Lock 1-4 cams, compress tensioner, remove belt, install new belt, undo tensioner. Leave engine the same, move on to 5-8 and repeat?

 

OLD? WTF? Didn't anyone tell you that 60 is the new forty! Fix it and drive it! Lost

 

I would look at your distrutors. Look for the correct spline alignment. Also check the weight advance mechanism. when they go all sorts of weird things happen.

 

Good advice, if everything lines up then it may be a simple ignition/spark problem which is breaking down under load.

 

Thanks to all who responded. I now have many things to look at. I will not be able to do anything with it for a couple of weeks due to other comittments. Will reply when I get back at it. If 60 is the new 40 I hate to imagine how I will feel after crawling around inside the wheelwell and kneeling on concrete all day when I am 70!!!!

Mike

 

As Lewis Blacks say about 40 being the new 60: "60 is 60. That's why they call it 60!"

 

BS!!!!! I'm 60 going on 39!! I would still be racing if I wasn't on my second pacemaker/defib. I am still considering vintage racing but when the green flag drops and the bull**** stops I ,as of yet, haven't been able to keep my pump from running too fast.
Mike, age is what you interpet it to be. Keep goin. "motion is lotion" Lost