Engine Problems, Help
Thread Starter
Racer
Joined: Sep 2005
Posts: 279
Likes: 1
From: montrose colorado
Engine Problems, Help
Hi All, Driving home two days ago the engine developed a dead miss. It threw code p0106 (map out of range) and a code for rich #1 bank. Took it to my tech friend at the local dealer, after some checks he said the map sensor system was ok and the manifold pressure was really low at idle and the scan tool showed no miss fires. He suspects some kind of internal failure he then said you may want to look at the valve springs. He knows my car has a comp 224-224/.581-.581 cam and 918 springs. The car makes no noise in the valve train but runs like crap. Does this sound like valve spring broken? What would be the steps to find the bad cylinder. Plug check? Compression check? Bank #1 I believe is the drivers side, just could pull the valve cover on that side. From what I read, this would not be the first 918 spring to break. Will be doing the checks tomorrow, tuner said they would warrenty the spring however they are 130 miles away. Would like to verify the problem first. Thanks for any and all help. 
Pro
Joined: Oct 2007
Posts: 538
Likes: 1
From: Niles Michigan
Pull your spark plug on #1 cylinder first, if nothing unusual check them all. Then do a compression test. These are the cheapest, easiest thing to check first before you pull your valve cover and or cylinder head off.
Le Mans Master
Joined: Aug 2001
Posts: 8,145
Likes: 1
From: Bradenton FLORIDA
DON'T drive it OR run it. Comp had a bad batch of 918's and pulled them all from distribution when they discovered it. (unlike some companies would) and have replaced any failures when verified. Excellent customer service on their part, but in the event you have springs from that batch (3-4 months ago) you may very well have a broken spring and I suggest pull the valve covers and closely inspect each spring for failure before doing anything else. If a spring has broken you do not want the valve to drop & do more damage.
Give us a call if you want to talk in detail on the spring issue. Good Luck!
Give us a call if you want to talk in detail on the spring issue. Good Luck!
Thread Starter
Racer
Joined: Sep 2005
Posts: 279
Likes: 1
From: montrose colorado
Yep, Broke The Spring
Compression check showing #1 cyl. dead, no pressure. All others good. Pulled valve cover and the second spring back was broken. I believe this is the exhaust valve. Talked to tuner today and they said most of the time you can just change the spring and all will be ok. The spring is still holding the valve up. I wonder what the chances are of the valve being bent? Since Comp had some bad springs would they pay for the valve change if necessary? Thanks for all the help. 
Le Mans Master
Joined: Aug 2001
Posts: 8,145
Likes: 1
From: Bradenton FLORIDA
You may be fine, the way to check is swap out that spring, and do another comp test. As long as the spring still holds the valve up, you may luck out, but I would bet the valve kissed the piston a few times.
As far as Comp, it was a single batch (3-4 months ago) and if they determined yours were in that batch, they may warranty & replace the springs, but I would not expect them to cover repairs, but I'm not Comp so that's just my thought. I would try replacing just the one & don't start it, just do a CT to see if the valve seats. Main thing is the valve did not drop, so any major damage was probably avoided. I have not seen a single major failure due to breaks from that batch, only minor failures like yours. Comp is good stuff.
Try and move the valve stem up & down w/the spring off (have piston at TDC first & take the retainer & spring off with compressed air fit to the cyl. and then hold it tight between your fingers so you don't drop it.)
Good Luck!
As far as Comp, it was a single batch (3-4 months ago) and if they determined yours were in that batch, they may warranty & replace the springs, but I would not expect them to cover repairs, but I'm not Comp so that's just my thought. I would try replacing just the one & don't start it, just do a CT to see if the valve seats. Main thing is the valve did not drop, so any major damage was probably avoided. I have not seen a single major failure due to breaks from that batch, only minor failures like yours. Comp is good stuff.
Try and move the valve stem up & down w/the spring off (have piston at TDC first & take the retainer & spring off with compressed air fit to the cyl. and then hold it tight between your fingers so you don't drop it.)
Good Luck!
Thread Starter
Racer
Joined: Sep 2005
Posts: 279
Likes: 1
From: montrose colorado
Update, Valve Spring
Hi again All,
Took the rocker off the broke spring and now the cylinder will hold air pressure, seems the pumped up lifter with the weak spring was holding the valve open just a bit. Got the spring off and the valve seems to move up and down smooth and rotate smooth. Looks like it may be ok. Will not get a new spring until wednesday, then will run the compression test again. I had to dust off some old tools to do this job it has been some years since I have done some real engine work.
The spring is susposed to be a Comp 918 blue stripe but the stripe looks green to me, wrong spring? Will have to talk with my tuner.
Will get back later with the final result.
Took the rocker off the broke spring and now the cylinder will hold air pressure, seems the pumped up lifter with the weak spring was holding the valve open just a bit. Got the spring off and the valve seems to move up and down smooth and rotate smooth. Looks like it may be ok. Will not get a new spring until wednesday, then will run the compression test again. I had to dust off some old tools to do this job it has been some years since I have done some real engine work.
The spring is susposed to be a Comp 918 blue stripe but the stripe looks green to me, wrong spring? Will have to talk with my tuner.
Will get back later with the final result.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
2027 Corvette vs The World: Every Model vs Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
Burning Brakes
Joined: Jul 2004
Posts: 855
Likes: 11
Hi again All,
Took the rocker off the broke spring and now the cylinder will hold air pressure, seems the pumped up lifter with the weak spring was holding the valve open just a bit. Got the spring off and the valve seems to move up and down smooth and rotate smooth. Looks like it may be ok. Will not get a new spring until wednesday, then will run the compression test again. I had to dust off some old tools to do this job it has been some years since I have done some real engine work.
The spring is susposed to be a Comp 918 blue stripe but the stripe looks green to me, wrong spring? Will have to talk with my tuner.
Will get back later with the final result.
Took the rocker off the broke spring and now the cylinder will hold air pressure, seems the pumped up lifter with the weak spring was holding the valve open just a bit. Got the spring off and the valve seems to move up and down smooth and rotate smooth. Looks like it may be ok. Will not get a new spring until wednesday, then will run the compression test again. I had to dust off some old tools to do this job it has been some years since I have done some real engine work.
The spring is susposed to be a Comp 918 blue stripe but the stripe looks green to me, wrong spring? Will have to talk with my tuner.
Will get back later with the final result.
Sorry to here about your problems. We never use conical springs because we found them to lose there spring rate very quickly. There are a lot of good dual springs on the market. IMO the Comp 921 are the best. Also any time one spring fails, there are always another waiting to fail. I would recommend changing them all.