Cadillac Owners Forum banner

Cam Question

2K views 17 replies 6 participants last post by  basscatt 
#1 ·
Bottom line history is that this 98 Eldo standard came with a different motor than advertised.( Block and vin don't match) Been through a lot but the latest is that I my big job guy changed valve cover gaskets. The lobe(?) on the cam for the water pump broke so he found a replacement, using the vin number. His cost. When I got it back it ran good except a very small idle thing, and it kept throwing codes for right and left fuel bank lean. Took it back and he found a couple of vacuum leaks but he said the numbers he was supposed to be setting the car at were all over the place. Replaced the intake gasket and still the "#s"were all over the place. Replaced intake manifold and numbers settled down but still not perfect. Said to drive it for a while and see if the onboard adjusts. It didn't and I still had the idle problem. Left it with him again when I was out of town and when I came back he said that the motor and vin #s don't match Which I knew but forgot to tell him. H e said he was checking to see if there was a difference in the cams . I had a thread at one time about this and I think the general concenses was that when they flip a head gasket issue motor, they normally don't swap the upper stuff.(cam) Am I making any sense? I told him I would talk to you people for you input also.
Thanks Kent
 
#4 ·
When I figured out that this motor was not original , with the six or seven digets on the bottom of the block, I know it was the base for a 300hp motor.From what this site told me it is what is on the top side that make the hp difference, and usually you don't change everythingbecause computer system is different. The Idle at stop is not smooth. Sometime almost imperceptible, othertimes almost semirough. Thought it was vacuum related to start with.Said they have checked everything. No codes anymore. If it was cam related you would think it would be consistant all the time(at idle.) It runs better than before I brought it in now, and that was great, except at idle. It didn't have the idle problem before. I called to find out what numbers he was talking about but he is gone till tomorrow so I'll have to wait.
 
#5 ·
so - your VIN Y motor was replaced with a VIN 9 motor at some point in time -

and during the cam cover gasket replacement -
the front intake cam was broken -
and the mechanic replaced it with a VIN Y cam -

that means the the front bank is running a different - actually correct - cam -
than the rear bank - that is running an incorrect VIN 9 cam -

the BEST solution would be to replace the incorrect rear - VIN 9 cam -
with the correct VIN Y cam - but that is going to be a LOT of additional work -

the SECOND BEST solution would be to replace the correct VIN Y cam -
in the front bank - with an incorrect VIN 9 cam -
so it matches the incorrect VIN 9 cam currently in the rear bank -

I have never heard of anyone running mismatched intake cams -
I doubt there will be any "damage" caused by continued use -
but I can't imagine the engine will ever run evenly or smoothly -
with mismatched intake cams -

if it were mine - MINIMALLY -
I would have the front cam changed to match the rear cam -
 
#10 ·
This is getting more and more convoluted. Do you know which intake cam the mechanic ordered and installed? Did he ordered the right one for the engine, or the right one for the car? Either way you have at least one wrong cam (maybe two). One would probably be even worse than both.


If it was cam related you would think it would be consistant all the time(at idle.)
Yes, I would tend to think so.
 
#11 ·
When the cam broke, Dan found a used one for a Y vin motor which he thought the car was. Upon receiving it he saw the old and new cam numbers didn't match. Realized the motor had been changed to a 9 vin. He said he micrometered it and said the only difference was in the width of the lobes. Now he should have researched more but he didn't. Now he is trying to find a reasonable$ 9 vin cam. He also said that the fuel trim #s were what he was referring to being all over the place. I will let you know what happens. So bottom line is that I have a 300hp standand Eldorado when he puts the correct cam back in. When I drove the Eldo back from Florida, I averaged 27.6mpg. Pretty high for an ETC or a STS, which is what the 300hp motors come in. Is that because the tranny is geared for a 275hp motor?
 
#12 ·
Yes ............. mostly. The cams, ECM/PCM programs, and final drive ratio all work together to give the VIN Y engined cars something like a 3 - 5 mpg advantage over the VIN 9 - on the highway during long drives. Both engine setups are pretty close when it comes to in-town and near suburban driving: It still takes low-end gas pedal to start the car moving.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top