Weird problem after cam install - Cam reluctor?? (pics)
07-12-2007, 06:31 PM
#1
Weird problem after cam install - Cam reluctor?? (pics) I think I've got the problem narrowed down, just need a little more info.
I'll try to keep this short so you'll read through all of it.
2001 camaro, bolt ons, cam, spray
Swapped cams, rest of valve train stayed the same, went from 233/239 to much smaller custom cam.
Swapped cams, install went fine other than battery was dead after words (car had been sitting for a week or so).
New battery went in, tried to start the car, it cranked and backfired out the exhaust. Decided what the hell, lets try it again. Gave it a little gas, car fires and idles OK but throws a P0343 and the tach is dead.
P0343: Camshaft position sensor circuit high.
So far I have:
Changed sensors
Monitored the signal from the sensor at the PCM with the engine running and while turning the engine over by hand, constant 11 V.
Today I pulled the cam at the advise of Kurt @ W2W who was nice enough to talk to me on the phone about this. I double checked the torque on the cam gear & cam retainer bolts to make sure the cam wasn't walking. They were all torqued to spec.
This is what I found:
I need to find out what the tolerances are, or hopefully someone can tell me just from looking that it is bad. I don't have a nice pair of calipers to get actual measurements, but you can certainly see the difference between the cams using the cheapo ones I have.
Stock GM cam on the right, new cam on the left dowel pins oriented the same. The cam that came out of the car is identical to the stock cam in the area of the reluctors as far as I can tell.
Rotated 180 deg
Calipers were set and locked in on the new cam and then compared to the stock cam. These pictures are of the stock cam.
O.D. Of the ring. This one's kind of hard to see, but it's ~1/16" larger than stock judging by eye.
The width of the rings are considerably larger on the new cam.
I can take the cam to machine shop and have it accurately measured if needed, but I don't know what the tolerances are so that won't really do me much good. Car is still torn down waiting to find out what to do, the cam that was supposed to come out is in there holding up the lifters
I'll try to keep this short so you'll read through all of it.
2001 camaro, bolt ons, cam, spray
Swapped cams, rest of valve train stayed the same, went from 233/239 to much smaller custom cam.
Swapped cams, install went fine other than battery was dead after words (car had been sitting for a week or so).
New battery went in, tried to start the car, it cranked and backfired out the exhaust. Decided what the hell, lets try it again. Gave it a little gas, car fires and idles OK but throws a P0343 and the tach is dead.
P0343: Camshaft position sensor circuit high.
So far I have:
Changed sensors
Monitored the signal from the sensor at the PCM with the engine running and while turning the engine over by hand, constant 11 V.
Today I pulled the cam at the advise of Kurt @ W2W who was nice enough to talk to me on the phone about this. I double checked the torque on the cam gear & cam retainer bolts to make sure the cam wasn't walking. They were all torqued to spec.
This is what I found:
I need to find out what the tolerances are, or hopefully someone can tell me just from looking that it is bad. I don't have a nice pair of calipers to get actual measurements, but you can certainly see the difference between the cams using the cheapo ones I have.
Stock GM cam on the right, new cam on the left dowel pins oriented the same. The cam that came out of the car is identical to the stock cam in the area of the reluctors as far as I can tell.
Rotated 180 deg
Calipers were set and locked in on the new cam and then compared to the stock cam. These pictures are of the stock cam.
O.D. Of the ring. This one's kind of hard to see, but it's ~1/16" larger than stock judging by eye.
The width of the rings are considerably larger on the new cam.
I can take the cam to machine shop and have it accurately measured if needed, but I don't know what the tolerances are so that won't really do me much good. Car is still torn down waiting to find out what to do, the cam that was supposed to come out is in there holding up the lifters
Last edited by calongo_SS; 07-12-2007 at 06:55 PM.
07-12-2007, 09:31 PM
#3
Do a search. There was someone else just recently that founds the same issue with the cam reluctor being undersized. Unless of course you're him.
the other thread/post was very recent. Wanna say last week. The same guy posted on the CF also. C5 section I believe.
the other thread/post was very recent. Wanna say last week. The same guy posted on the CF also. C5 section I believe.
07-12-2007, 10:17 PM
#5
I went through all of the same things you did and after pulling the cam and checking it numerous times I finally got it to run right. After sitting there letting int crank over for roughly 3-4 minutes ( not continuous of course) the computer finally figured out the relationship of the CKPS to the CPS and it started right up and has ran great ever since. Everyone told me it had to be something else and that the computer would figure it out within a matter of seconds and flip the firing order 180 but that was not the case on my car. Do a search for threads I started and I described the symptoms better there. Good luck.
07-12-2007, 10:34 PM
#6
I must have started the at least 6 or 7 times and every time it did the same thing. I can't see myself putting the cam back in again for a second time to see if cranking longer will solve the problem. If I can not confirm the cam is the problem I will send it back to the manufacturer.
Also I have monitored the signal from the cam position sensor and it is not there. No re-learning that.
I did let the car idle for 4-5 minutes hoping it would fix itself, and no dice.
Also I have monitored the signal from the cam position sensor and it is not there. No re-learning that.
I did let the car idle for 4-5 minutes hoping it would fix itself, and no dice.
Last edited by calongo_SS; 07-12-2007 at 10:40 PM.
07-12-2007, 10:45 PM
#7
Originally Posted by calongo_SS
I must have started the at least 6 or 7 times and every time it did the same thing. I can't see myself putting the cam back in again for a second time to see if cranking longer will solve the problem. If I can not confirm the cam is the problem I will send it back to the manufacturer.
Also I have monitored the signal from the cam position sensor and it is not there. No re-learning that.
I did let the car idle for 4-5 minutes hoping it would fix itself, and no dice.
Also I have monitored the signal from the cam position sensor and it is not there. No re-learning that.
I did let the car idle for 4-5 minutes hoping it would fix itself, and no dice.
Did you check continuity back through the plug to the pcm?
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07-12-2007, 11:06 PM
#9
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It looks to me as if the bearing journals are different widths. The cam on the left is clearly narrower. I would think that the narrower journal would pull the tone ring out of line with the sensor as soon as the timing sprocket is tightened. Try standing both camshafts on there noses side by side and see if the tone rings are in the exact same position on the shaft. It just looks like the one may get "sucked" further forward when all the bolts are tight.
07-13-2007, 12:49 AM
#10
Good idea, here's some more comparisons..
Standing side by side on the back of the cam:
Stock cam on the LEFT
Cams still standing on end:
Looks OK, but when you think about it the cam gets pulled forward into the cam gear. I lined up the front of the cams with a straight edge like so:
Stock cam is on the LEFT
Scanning back keeping the front of the cams aligned:
Stock cam is on the TOP
This looks WAY off to me.
Rotate them 180 to line up the respective reluctor:
This one doesn't look too bad.
I realized as I was resizing the pictures that I grabbed a rag from the box covered with cute little hearts. Please, I deserve to be harassed for that.
This looks like the root of the problem. Anyone disagree? I will compare the current "bad" cam to the cam that was coming out of the car eventually and see if it is closer to the stock cam.
Standing side by side on the back of the cam:
Stock cam on the LEFT
Cams still standing on end:
Looks OK, but when you think about it the cam gets pulled forward into the cam gear. I lined up the front of the cams with a straight edge like so:
Stock cam is on the LEFT
Scanning back keeping the front of the cams aligned:
Stock cam is on the TOP
This looks WAY off to me.
Rotate them 180 to line up the respective reluctor:
This one doesn't look too bad.
I realized as I was resizing the pictures that I grabbed a rag from the box covered with cute little hearts. Please, I deserve to be harassed for that.
This looks like the root of the problem. Anyone disagree? I will compare the current "bad" cam to the cam that was coming out of the car eventually and see if it is closer to the stock cam.
07-13-2007, 08:46 PM
#11
Two issues you need to be concerned about. Alignment of the tone ring fore and aft, and the air gap. The best way to check the air gap is to put each cam in the block, and using a depth mike check the depth of the tone ring from the edge of the block where the sensor would mount. And then measure the length of the sensor. The difference is your air gap.
And yes, the other guy with the same problem had his car at W2W. Try a search on here and the CF, in the C5 section. C5 tech I believe. Its probably not more than 3 pages back. It was very recent.
And yes, the other guy with the same problem had his car at W2W. Try a search on here and the CF, in the C5 section. C5 tech I believe. Its probably not more than 3 pages back. It was very recent.
07-13-2007, 10:42 PM
#12
Well being as I can see the difference in the position of the rings with my naked eye, I'd say there's a problem there.
I will be taking the cam to a friends shop tomorrow to take some accurate measurements. He's got 5 or 6 stock cams laying around & some nice calipers so we'll get a good average and compare things from there.
I will be taking the cam to a friends shop tomorrow to take some accurate measurements. He's got 5 or 6 stock cams laying around & some nice calipers so we'll get a good average and compare things from there.
07-14-2007, 04:12 PM
#15
I took the cam in question and the stock cam over to a friends shop for some more precise measurements. We also compared the cam to another aftermarket cam.
Overall the cam is .065" taller (longer) than both of the the other cams
The width of the rings on this cam are .140 & .130. The stock & other cam's rings were both .100 & .100
The rings stand up .115 from the base & .150 on the stock and the other aftermarket cam.
The bearing journals are .775 & .790 on the stock cam. The other aftermarket cam was in between these two.
The part that really concerns me is that the front ring will be .087 farther back in the block, and the back ring will be .05 farther back in the block compared to the stock cam & the other aftermarket cam.
With all three cams standing up on end and looking at where the bearing journals line up it is evident that each journal on this new cam is further and further off from the stock cam.
This is the 4th journal back from the front of the cam, it's obvious it would be pushed further back in the block. The third isn't quite this bad, and the 5th is even worse.
These pictures illustrate how far off the rings are. The cams are standing on the front with only the alignment dowel hanging off the edge so they'll stand flat.
I'll be calling the cam grinder on Monday to see how they will correct this.
Overall the cam is .065" taller (longer) than both of the the other cams
The width of the rings on this cam are .140 & .130. The stock & other cam's rings were both .100 & .100
The rings stand up .115 from the base & .150 on the stock and the other aftermarket cam.
The bearing journals are .775 & .790 on the stock cam. The other aftermarket cam was in between these two.
The part that really concerns me is that the front ring will be .087 farther back in the block, and the back ring will be .05 farther back in the block compared to the stock cam & the other aftermarket cam.
With all three cams standing up on end and looking at where the bearing journals line up it is evident that each journal on this new cam is further and further off from the stock cam.
This is the 4th journal back from the front of the cam, it's obvious it would be pushed further back in the block. The third isn't quite this bad, and the 5th is even worse.
These pictures illustrate how far off the rings are. The cams are standing on the front with only the alignment dowel hanging off the edge so they'll stand flat.
I'll be calling the cam grinder on Monday to see how they will correct this.
Last edited by calongo_SS; 07-14-2007 at 04:30 PM.
07-14-2007, 06:25 PM
#16
Another check I just did.
With the old cam in I put the retainer plate back on, & put the cam gear on (no chain).
I put a volt meter on the CMP signal wire, turned the key to "run" and turned the cam by hand. Low and behold it switches from 0 - 12 v just like it's supposed to. I had tried this before with the new cam while the engine was together turning the motor over by the crank and while running and it stayed a constant 12 V.
With the old cam in I put the retainer plate back on, & put the cam gear on (no chain).
I put a volt meter on the CMP signal wire, turned the key to "run" and turned the cam by hand. Low and behold it switches from 0 - 12 v just like it's supposed to. I had tried this before with the new cam while the engine was together turning the motor over by the crank and while running and it stayed a constant 12 V.
07-15-2007, 01:18 PM
#17
TECH Senior Member
That's ludicrous that they could sell that cam to you, very poor quality control, and it cost you a bunch of your time/money...
From the difference measurements you described, looks like the tone ring is too far from the sensor and misaligned to it (everything adds up);
You have come up with the procedure to ensure a new cam will work with the sensor:
a. compare side by side for exact location of tone ring (and journals while we're at it);
b. measure "height" or diameter of tone ring and compare;
c. test install the cam and turn it while observing voltmeter.
This has been a very interesting read, thanks, I'm glad you have found the cause.
From the difference measurements you described, looks like the tone ring is too far from the sensor and misaligned to it (everything adds up);
You have come up with the procedure to ensure a new cam will work with the sensor:
a. compare side by side for exact location of tone ring (and journals while we're at it);
b. measure "height" or diameter of tone ring and compare;
c. test install the cam and turn it while observing voltmeter.
This has been a very interesting read, thanks, I'm glad you have found the cause.
07-15-2007, 02:01 PM
#18
I'm glad I could give you some entertainment at my expense, lol.
Yes, the lesson that I have learned is not to assume that any engine part will be correct. The thing is I actually quickly compared the cams before I threw it in. In the past I've always just put them in assuming things would be ok.
Just to reassure myself that I am correct before I call the manufacturer tomorrow, I put the new cam back in. I put the retainer plate & cam gear on as well and left the chain off like above. Turned it over by hand while monitoring the CMP signal wire and it stayed a constant 12 V.
I've heard good things about the cam manufacturer, but I'm not impressed. This is the second cam they sent me. The first one I was able to tell it was incorrect by looking at the cam card. They told me they accidentally ground it from the wrong blank.
I guess I'll see how they deal with a very unhappy irritated customer tomorrow.
Yes, the lesson that I have learned is not to assume that any engine part will be correct. The thing is I actually quickly compared the cams before I threw it in. In the past I've always just put them in assuming things would be ok.
Just to reassure myself that I am correct before I call the manufacturer tomorrow, I put the new cam back in. I put the retainer plate & cam gear on as well and left the chain off like above. Turned it over by hand while monitoring the CMP signal wire and it stayed a constant 12 V.
I've heard good things about the cam manufacturer, but I'm not impressed. This is the second cam they sent me. The first one I was able to tell it was incorrect by looking at the cam card. They told me they accidentally ground it from the wrong blank.
I guess I'll see how they deal with a very unhappy irritated customer tomorrow.
07-27-2007, 07:23 PM
#20
Just thought I would update this. I sent the cam back to the manufacturer, they looked at it, and figured out it was bad. One of their CNC lathe's had a bad controller board and caused it to not be as accurate as it should be.
They had no blanks for this grind that were good, so they had to purchase a blank from another manufacturer. It took them 4 or 5 days to get one to me from the time they got the bad one.
They refunded the purchase price of the cam and offered to refund the price of the new CMP sensor I bought while trying to find the problem if I sent it in to them.
New cam is in the car and everything if fine.
They had no blanks for this grind that were good, so they had to purchase a blank from another manufacturer. It took them 4 or 5 days to get one to me from the time they got the bad one.
They refunded the purchase price of the cam and offered to refund the price of the new CMP sensor I bought while trying to find the problem if I sent it in to them.
New cam is in the car and everything if fine.