3rd cylinder having major problems

[Sleeper87]

Im having some major problems with my motor....I had it rebuilt and the camshaft has gone twice now....the lobe on #3 cylinder keeps wearing out for some reason....this is the 2nd camshaft they will be puttin in my car....Metal shavings in the oil filter. Car went fine for about 1,100 miles or so and then the car developed a knock at higher rpm wich come to find out is that #3 cylinder lobe on the cam....I had the motor rebuilt in the 1st place because of a knock in the motor wich was a bent rod on the #3....something is up...anyone know what.....I was told that oil is a factor big time....is something blocking the passage or something? I dunno you tell me what u think thanks...
Sleeper87

 

[Red Regal T]

Sounds like a very frustrating problem. You stated you had someone do the rebuilding. It seems to me, they should have the expertise to figure out what's up. Sorry I can't be more helpful. Good luck!

 

[The Radius Kid]

You been wiping #3 exhaust lobes?You've gotta be careful which brand of cam you put in your engine.Buicks are known as problem childs when it comes to cam wear.The way I hear it from a lot of my buddies[street racers],most cams these days are being ground on some pretty crappy blanks.Compound that with the Buick's lack of oil to the cam,and you've got a problem waiting to happen.

 

[Sleeper87]

The dealership themselves will be doing the install of the new cam and the investigation...they are currently planning on sueing the machine shop for their Mistakes...I guess im not the only one...it was a NEW cam that went in it...and a new one is already ordered im guessing its OEM from Buick or GM whomever....but if anyone has these same problems please let me know how and if you have fixed it....What other bugs should i be on the lookout for....When the car gets returned to me i have the Turbo TA FPR to put in it so i can run my Chip *Thrasher* made for stock fuel injectors on 60psi of fuel.....Thanks
Sleeper87

 

[ZNX]

some food for thought

Many have wiped #3 exhaust cam shafts - also me! stock, never touched, 53,000 miles
seems to occur more with new cams and especially high pressure springs
some tuners claim with proper break-in, they never experience this
FACT #3 exhaust lifter bores in the block(yes, even stage 2 on centers which i had two of) is moved .100 as compared to other cylinders - meaning distance from lifter to lifter is 1.600 in 5 cylinders and 1.500 on #3. THIS IS NOT A GOOD THING. and no, the cam lobes on #3 is not changed to compensate for this. Why did buick do this? who knows... Ken D. told me he thought cause the V-6 was originally a V-8 and they loped off 2 cylinders and this may have been for strengh of webbing at that point - but even he was not sure.
So why do some wipe and some don't? - worn lifter bore(you mention you bent the push rod?) Loose timing chain, improper cam taper, worn springs, (your sig says you have LT-1 springs... do you have the correct LT-1 springs?) improper break-in.
IMO = all of the above and a bunch of others, that's why i went billet roller.
As a note, the G.S.C.A. has recognized in their news letter that #3 is off .100 and they grind their cams with more lobe taper. So IMO if you go flat tappet, that's who i would buy from.
Also, the OEM turbo cam has not been available for quite some time. I would find out just what your buick dealer is giving you.
H.T.H. a little, best of luck.

 

[blackbuick87]

Absolutley have the lifter bores on that cylinder checked. Also make sure the lifters are turning in the bore and not wearing in the same place all the time. Also I would dump the LT1 valve spring for something a little softer. I have read here that Comp Cams 980s have less open pressure. Finally I would get a really good aftermarket cam and lifters, like a Crane or Comp Cams unit. They will have better heat treating for better wear resistance.

 

[UNGN]

Thinking outside the box, couldn't someone run a little tube (like 1/8" diameter) from the turbo return line hole and direct it to the #3 exhaust lobe. Maybe it wouldn't fail so often if it was swimming in oil

 

[Trois Buicks]

A set of "CamSaver" lifters would also be a good idea. They are available from Comp Cams and the price was $75/set when I bought an extra set a couple of months back. I used a set of these when I changed my flat cam at 134K-- they are hydraulic lifters with a small groove machined on one side so oil can run down the side of the lifter and drip onto the cam lobe.

HTH,
Morgan

 

[Sleeper87]

again, my mods are NOT on the car....all are sittin in my apartment...NO mods to the car whatso ever....
Sleeper87

 

[RDavis]

#3 cam lobe worn out

Been there, better check your bottm end out and replca that oil pump. On this rebuild I will have a .002 small groove put in the lifter bore to oil the camshaft. Goodson supply has the tool to do this
Thanks Rod