ignition timing?

[Shane Sawatzki]

So the new head and the new turbo are on, and after putting it all back togethor iv noticed 1 of 2 things. first, minor and silly forgetfulness, there is no cotter pin on the wasgate rod lol...:| thats simple enough, heres the more complicated question, before the head job...the car idled perfect...now not so much..it sounds alot different and the only way i can describe it is to say it sounds cammed, the timing belt marks are right, we triple checked that. my dad figures the cam angle sensor needs to be adjusted and i think thats the ignition timing? he isnt 100% sure either he works for land rover lol and this isnt a range rover. SO would adjusting the cam angle sensor and using a timing light be adjusting the ignition timing on my car?

[Ryan Lore]

either you have an air leak in your intake plumbing or the timing marks are off. Did you check the marks on the sprockets with a straight edge? Do all 4 marks line up, or are the outer marks higher or lower than the straight edge. If they are higher, by how many teeth?

[Shane Sawatzki]

okay so after taking the t-belt on and off 5 times today, the belt timing is right. the number 4 cyclinder is not firing...wires are good, plugs are good what else will cause this cylinder to not fire? I dont see any vacuum lines not hooked up...seems like everything is hooked up...now its just running on 3 ...and is dead on a hole?

[Chad Giffen]

One thing I always do after a timing belt change is a compression test. If you get spark and your injector harness is not snapped from being brittle, you should be fine.

Do a compression test.

While your doing that, disconnect all the injectors except the number 4 cylinder and see if you can smell fuel or not. Other than that check your coil connections. It either one of those 3

[John Hartman]

after you do a compression test on number 4, pull the number 4 injector wire and put a 'noid light on it to see if there is any pulse there.

[Shane Sawatzki]

okay so compression in cyl 4 is 25.  before it was taken apart it was 130. im boggled. :| 

[John Hartman]

did the timing belt break?  Or skip?  Is that why you took it apart?  If so, rarely do any engines of this type get away with that, usually 8 valves touch pistons at least, so if you only have 1 or 2 bad ones, you got lucky believe it or not.

You took the head off right?  If so, you had the cams out. And as such, if you didn't allow the lifters to sit for a bit(a couple hours) with the engine at TDC, they can still be extending the valves and when you spun it over to start it, you bent a valve or 2.

Also, did you replace the head with just any used head?  Because a slightly burned exhaust valve will do this.  You can get even 80 psi with a slightly burned exhaust valve.  I did one at work, 2 and 3 had 55 and 10 psi. The burn in the 55 psi cylinder was barely noticable unless you were looking for it and the other was quite noticable.

[Chad Giffen]

Well considering your engine was running on 3 cylinders, the timing is definately fine. sounds like head gasket sealing issues to me which really really sucks.

do the oil check to make sure it is not the rings and then you know its your headgasket. Did you get the head checked for flatness? Did it have a good urface finish for sealing? Sounds like it might be warped.

Usually when I do heads, I will get the head shaved but do my best on the block. Then at least on surface is totally good.

[Chad Giffen]

John has a point, what were your reason for maintenance exactly?

[Chad Giffen]

Honestly man, I would pull the head to be safe and look for valve contact. You cannot risk otherwise. OEM PIstons are soft and you dont want little chunkers floatin around in there. Either way John is right, or your lucky and its your head gasket.

Pull the head. One thing you can do is take it to a machine shop and they will flow test it for you to let you know about the valves. If its minor damge (which im assuming because your #1 cylinder seems ok) you may be able to save the head.

What was your compression in the #1 cylinder might I ask?

Here is what I mean by soft pistons....    my first Talon (non-Turbo) had this happen to it.



See the hole in the piston? Mmmm  look at that bearing too!

[Shane Sawatzki]

cyl #1 had 135...#2 had 130 #3 had 135 and #4 had 25.  the reason for the head swap was the head that was on my car needed valve seals really bad and had 3 broken off exhaust manifold studs, so i figured id just pick up a used head and rebuild it with new valve seals and everything and put it on and things would be good...guess not...anyway the head is coming back off tonight to see whats up

[Matt Mann]

Shit..If your head just needed valve stem seals that would have been an easy fix. You can replace them with the head on the car. take the plugs out throw rope down Cylinder 1 and 3  get the engine TDC on Cylinder 1 and rent or borrow a miller valve spring remover and easy as pie. I've done it that way before worked great. No messing around with the head and HG took me 3 hours or so to do. But its too late now.
those exhaust studs are a PITA I replaced a few with the larger sized studs (Less chance of breaking next time) Use a lot of WD-40 and I always talk to the stud tell it not to break..seems to work so far...lol
Shane is your car running right now? Haven't seen it lately.

[Shane Sawatzki]

yea well the studs that were broken were the far right bottom one and the 2 behind the turbo so to drill and heli coil them the head almost had to come off anyway to get at them easy and straight. so thats why i picked up a head with good studs. but no my car has been off the road since friday...  should be back up again sunday at the latest...i got my dad working on it and im driving my moms 06 TDI jetta automatic  lol but any other ideas?? im hoping its my cheap head gasket...yes im sorry guys i got the hg off ebay...  so i guess i learned my leason if that turns out to be the problem...or if its a tagged valve or 2...i have plenty of un bent valves...I have 2 complete cyl heads. and if the head is no good looks like im taking the new valve seals outa the new head and rebuilding the head that I took off with the broken studs, then ill just heli coil the studs... but thats worse case scenario i think...

[Chad Giffen]

well keep us upto date, which ever way you decide to go. The only way ou will know for sure whats going on without reassembly of eberything again is to get that head flow tested for that cylinder. Or you could try a water check I guess. I've never tried the water test before and I dont know if good valve seal with seal water in the intake tract etc.

But in this case I would try it. Put water in the intake and exhaust tract of the #2 cylinder and see if it holds the water under spring tension. If so, test that on the #4 intake and exhaust tracts and see if the same happens. Then you know if its your valves or your head gasket.

Thats what I would try anyways. It may sound quick and dirty but that just might work.

[John Hartman]

if the head is off, carefully inspect each valve and seat area.  When the cams are out, all the valves will close.  go in a dark room, and put a flashlight down each exhaust port and intake port, if you see light on the chamber side around a valve its bent, burnt or the seat is damaged.