Tarek9xx

I have no one to blame but myself. Not the first time installing the intake camshaft, but it must've dislodged itself from the locating pin (or I mistakenly thought it was in), and it just snapped as I turned the bolts on the bearings...and it broke my heart with it.

Does anyone know if these are replaceable? I know the cam covers and heads are matched sets, but I was wondering about the camshafts themselves.

Should I be looking for a new (or good used) camshaft or am I totally screwed and must replace the head? And if you have, or know of, any of these parts, I would greatly appreciate it if you'd let me know. It's for Bank 2, if it makes a difference

Thanks in advance

hardtailer

Replace cam only as it's not matched to head and cam cover or to the exhaust cam for that matter.
Personally I would look for a used cam in good condition.

ronny062

A USEED CAM IS NOT ALWAYS THE BEST IN MY OPINION

Noz1974

I have some spare cans off a five chain not sure if they different ?

ZuffenZeus

Yes... the varicam Camshafts on 5-chain engine are very different from the Varicam+ 3-chain camshafts that support nested tappets and how they support variable valve timing.

ZuffenZeus

Is this what happened to you?

Sam-Son

Are the '99 3.4s 5 chain?

ZuffenZeus

yes.... the 3.4L is a 5-chain engine.

Sam-Son

thank you
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Tarek9xx

Yes. I didn't use a cheater mark, and so I didn't realize it moved on me during installation of the shaft assembly, which includes the bearing, and obstructs the view. I was also working on the engine in its normal position/orientation, on a table. Therefore working against gravity. I had been extra extra careful to avoid just that very mistake, and had installed and removed multiple times just because I was nervous about getting the timing wrong, and when I finally figured out the timing (and the trick to remove the chain guide rails for ease of assembly), I made that other mistake that Ive been so keen to avoid. I heard a mild "click" as I installed one of the bearings, and it sounded as if the bearing itself snapped in place, and so I never realized the shaft itself had broken. discovered it later on as I turned the engine 360 degrees to take the slack out of the chain on bank 1 for assembly....and yes realizing that I did it with stationary valves in the open position on cylinder 5, added insult to injury.

....but that's still not the end of the problem. In checking leak down numbers to determine if I damaged the valves as I turned the engine by hand, I discovered 75% leak down on cylinder 1, with air blowing by the piston rings to the oil pan. All other cylinders were in the 10% range. Ironically, the one I suspected to be damaged (cylinder 5), was at 9%. So may be the broken camshaft led me to discover my true smoking problem.....and all along I had believed it was the AOS (or may be both?), and never even considered a leak down test as part of the diagnosis.

I'm also suspecting that overfilling with oil started a domino effect that MAY have contributed to the blow-by on cylinder 1
So yes I'm embarrassed at many levels. That's not typical of me. May be I need a vacation

...but at this point, what matters is what to do about it. A complete teardown is on the table. So let's hope I go on vacation first

Tarek9xx

Thank you! Helps reduce the scope of my problem!
...starting with heart medication

Tarek9xx

Thanks for your input. I've been wondering about that too. What are the typical issues to look for in a used camshaft? I'm thinking the risks associated with the handling are not to be ignored, in addition to straightness and wear on the bearing and lobe surfaces, none of which are easy to measure with the tools available to me.

It looks like I also have oil blow-by on cylinder 5. Therefore as I quantify the scope on this problem, I'll have to weigh the risks of a used camshaft versus new, which seems to be priced around $700 +/-

hardtailer

Based on your own experience I think you don't have to worry about its straightness as they obviously don't bend but snap as soon as they are bent.
Wear is visible before it's measurable so look for score marks on the bearing surfaces and pitting at the tips of the lobes in addition to score marks.
A pair of calipers should suffice to ensure it's not reground.
All of this requires to find one locally to inspect it yourself but perhaps detailed pictures will enable you to judge the condition of a 2nd hand cam from a distance. Add to this that the cams don't have a reputation of wearing the lobes or such and 2nd hand makes an attractive proposition.

amargari

I may have one I would let go for a cheap price. I picked up a 997 3.6 engine yesterday for the block and it came with the bank 2 head. Let me know if you are interested.