1998 2.4 Camshafts in 1999 T5

[RickHaleParker]

The bubbling does not look like a real serious problem. I think lapping the valves would correct the leakage. If you go through the process might as well replace the vale stem seals while you have the valves out.

[xApprchsNfnty]

The bubbling does not look like a real serious problem. I think lapping the valves would correct the leakage. If you go through the process might as well replace the vale stem seals while you have the valves out.

I hope it's not a serious problem. But check out cyl#5 and cyl#3 (they're worse!):

https://youtu.be/1iMuJtyC7zs

https://youtu.be/LZ8fGlZR3Y8

And here's cyl#1 for continuity:

https://youtu.be/WDlUF1v82SU

Lapping the valves I think would make a big difference but I can't wrap my head around how this condition simply 'showed up' by replacing the timing belt and I don't think I'll be satisfied until I know. Even if I rebuild the head and get it running again, unless that clarifies the problem, I won't feel like I won.

[abscate]

One place you can mess up onaVVT car is when you dial the crankshaft back to set the cam.

If the tensioner locks over at The high tension point, you can turn the crank without turning the cams.

That’s why you always validate the timing marks with two full crank revolutions after tensioning.

[bmdubya1198]

Right, but that shouldn't affect the intake valves. Only the exhaust, which sounds like they're sealing. As long as the cylinder is at TDC when testing, that's the important part.

Wow, that's a lot on cylinder 5! Rick makes a good point on lapping the valves, but I don't know. That looks like a pretty high leak down to just need lapping. But I'd love to be proven wrong here.

[xApprchsNfnty]

...dial the crankshaft back to set the cam...

I'm not sure I did this. I essentially did exactly these steps except that I removed the intake pulley too to replace seals:

https://www.youtube.com/watch?v=o4uLvH1 ... =emb_title

I already had the belt off when I locked the cams, kept them locked to put the new belt on, clocked the exhaust pulley fully CW (where the marks lined up), and then set tension. After removing the locking tool, I confirmed the marks were still on and rotated it at least 2 times. But before the first start it was rotated many times, no obstruction, no loud noises. So as far as bent valves go, unless it skipped teeth on the first crank, and then they miraculously skipped back, I can't think how there would have been any contact. Although I'm sure stranger things have happened

Some other things that may be worth noting, I'm just throwing everything out there that I did during this job:

Recall that I initially broke the locking tool bolt off in the cam. I drilled/tapped and was able to use the tool correctly. Maybe I twisted the cam or put excess pressure on the valves? Seems highly unlikely.
I pulled the injectors and replaced filters/o-rings/plastic part on the front of the injectors. All still intact when I pulled it yesterday.
Replaced PCV banjo bolt with newer revision (w/ check valve) and cleared the system (original banjo bolt was the only blockage).

[bmdubya1198]

I don't think removing the bolt would have affected the valves, this is definitely a strange situation though. If there is in fact valve damage, the belt must have slipped at some point.

[abscate]

The VVT HUB needs to be torqued to the locked cams one tooth advanced from the timing mark, fully rotated clockwise

You then time it to the marks.

That would not Bend valves though

[xApprchsNfnty]

Soaked in Marvel Mystery Oil and tried cleaning the edges/seats as best as I could but there was no change in compression. I bought some wire brushes but they were too big to get in between the valves and the seats so I couldn't use them. I'll be waiting at least a week for that endoscope to show up. In the meantime I'll probably time it again just to be sure (although at this point, if it were a little out of time, I don't think that would result in such low compression). And if timing it again and looking inside doesn't help solve it, I guess I'll be rebuilding the head and I'll probably clean/re-ring the pistons while I've got them there.

Can't believe all of this just from trying to replace a cam seal...

[xApprchsNfnty]

The VVT HUB needs to be torqued to the locked cams one tooth advanced from the timing mark, fully rotated clockwise

You then time it to the marks.

That would not Bend valves though

Hmm, I didn't torque it advanced at all. I did it the way it was in the video: pre-loaded it all the way CW to where the marks were aligned, then torqued it down. Does that not work? What's the intention of advancing it and then backing it off?

[bmdubya1198]

I don't think I've ever torqued it in the advanced position... I only have two hands! Lol
Maybe that's why mine grinds occasionally? But I'm pretty sure that's general wear on the hub, they tend to do that over time. I always seat the bolt, adjust the hub to line up the mark to the timing cover alignment mark while advanced, then let go and torque. Double check that it advances to the alignment mark, then install the belt and set tension.