Cam Timing, Help Needed

[Turbo Tim]

Recently I got my 100 000km service done at a local regular mechanic.

After getting the car back I had a huge problem with it pinging everywhere, especially light load and low throttle. I went back and they 'rechecked it' but it made no difference. I had to drive 300km to brisbane that afternoon so did and babied it as much as possible. Once i got to brisbane I got a timing light and checked the timing, was around 30-35 degrees BTDC. We put the timing back to where it should at 15 degrees, effectly pulling 15 degrees out of it. To get to 15 degrees the CAS was nearly at full retard.

The car still hasnt been right, has been a bit slow and quite 'surgey' in how its been accelerating, surges to about 5k rpm then wont accelerate too much harder. I had troubles getting up a steep driveway the other day too, the thing just wanted to stall unless I just about did a big launch.

Tonight I got the shits and pulled the top cam cover off. When I line the crank pulley up on the yellow TDC mark on the lower timing cover, both the exhaust and intake cam are both one tooth too far clockwise (advanced?) See crappy pics. I have marked the indentation on the pulleys and the marker on the timing cover is white already. I have tried to draw lines to eliminate paralax error, but difficult with a camera.

When I line the exhaust and intake cams up with there correct markers, the crank pulley is at about 15 degrees BTDC (the 3rd mark on the balancer past the yellow TDC mark). Im guessing this is pretty conclusive that they have got the timing out a tooth on both (crank pulley wasnt spot on when they did it?)

Am I right or is it right already,

Just want some advice before i go there tomorrow and potentially make an arse of myself.

Oh yeah one other thing, there is an oil leak up there too somewhere. Cam seals were done but there is a puddle on top of the water pump body, so should I be on to them about this as well.

Thanks,

Tim.

Edited October 31, 2007 by Turbo Tim

[Turbo Tim]

I just reassembled before going back there tomorrow.

I got a better pic of the intake cam. Line up the tooth with the letters that run along the teeth, the T on the incorrect tooth and the M on the correct one, makes it bloody obvious doesnt it!

[QWK32]

most timing lights double the timing reading on skylines. so really 30 BTDC is actually 15 BTDC. what you have done is take your timing back to 7.5 BTDC or really retarded hense the pinging and slow/sluggish feeling.

[Turbo Tim]

Which then returns to the question of why dont the timing marks line up and why was it pinging its ring off with the CAS in the original position they just bolted it back onto.

Im not sure about the doubling deal, but i think thats a discussion for another time. At 30 degrees (on double theory 15 degrees) i couldnt climb a slightly incline at 100 with it pinging significantly!

[QWK32]

when you cam pulleys are lined up on thier marks the crank pulley should be on the tdc mark, yours sounds like it isnt.

i am sure about the doubling deal i've seen it many times. depending on if you have enough of the timing signal loop to wrap around the timing light inductor if you wrap it around twice it gives you the correct reading without haveing to half the value (using 30 as 15).

[Fry_33]

Looks like it isn't lined up to me. The harmonic balancer can only go in the correct position so if the cams don't line up the belt is installed incorrectly.

Take copies of the pics down to the "performance shop" and don't take no for an answer.

I had a workshop do my timing belt and after redoing it myself last weekend am kicking myself for not doing it in the first place.

Good Luck

[Turbo Tim]

Yeah i get the feeling I might end up doing it myself as well. Not happy either way.

Wasnt either a performance shop, just a regular certified mechanic, would have thought they would do enough timing belts on various things for it to be a drop in the ocean. I guess it could have gone unseen if i didn't check it myself though.

[Fry_33]

In my opinion it is unforgivable and stupid to put the timing belt on like yours. Most engines these days are an interference design ie, valves and pistons can meet if timing of the two is out. This is obviously bad as when valves and pistons meet the results are not pretty, and usually expensive.

Once a timing belt is put on it should be checked and maybe double checked that all the marks line up. You can put the marks on the edge of the belt and then put it on. That way if the marks on the belt don't match up with the ones on the cams then you need to redo it. As long as the marks all line up you can't go wrong really.