S2000 Misfiring randomly
#1
S2000 Misfiring randomly
Hey there. Yeah, I'm new, but definately not a newbie. The reason I'm posting here is about my lil' sister's S2k. I think it's an 02 model, about 90k miles. Well, the CEL was on, so she took it to the dealer upon my recommendation. Seems to me the dealer would be the most knowledgable and would be able to fix it with the snap of a finger. Well, apparently not. From what they said it had random misfire codes on all 4 cyls, but nothing regular, or a hard skip. Just randomly missing here and there. Well, after 3 hours diagnostic time, and a set of spark plugs, the problem still exists, but is limited to cyl 2. So then the tech says he swapped the #2 injector to cyl 1, and 1 begins to misfire some, but cyl 2 doesn't quit misifiring completely. Then they call me and want me to authorize a valve adjustment. I'm calling BS.
My issue is this: I'm a BMW master tech at a BMW dealership, and I'm not an idiot by any means. Misfires are not hard to fix in my experience. I doubt the valve adjustment will fix it. I tell them to check/adjust them, but I'm not paying if it doesn't fix it (which I really don't think it will).
First, why wouldn't the S2k have hydraulic valves like every other modern day engine (other than the S54 in an E46 M3) that don't need adjustment? And 99% of the time, valves get looser over time, and not tighter, therefore would be highly unlikely to cause a misfire. Am I right?
My question is this... is there anything I can tell them to check or replace (or check myself if I end up having to fix it)? What would cause a random misfire that doesn't consistently happen on the same cyl every time? On a BMW, misfires are 90% of the time caused by an ignition coil, or the coil boot (part between coil and plug, effectively the "spark plug wire", although only a couple inches long). So what am I dealing with? If it was a bent valve, or compression issue, it would be a hard skip that happened every time that cyl fired, not something random, correct?
Only wish I had some Honda experience, but I'm a BMW tech, not Honda. But, an engine is an engine. Please help, or give any info you know. If any of you are on bimmerforums, you know I'm on there all the time lending my expertise. Thanks.
My issue is this: I'm a BMW master tech at a BMW dealership, and I'm not an idiot by any means. Misfires are not hard to fix in my experience. I doubt the valve adjustment will fix it. I tell them to check/adjust them, but I'm not paying if it doesn't fix it (which I really don't think it will).
First, why wouldn't the S2k have hydraulic valves like every other modern day engine (other than the S54 in an E46 M3) that don't need adjustment? And 99% of the time, valves get looser over time, and not tighter, therefore would be highly unlikely to cause a misfire. Am I right?
My question is this... is there anything I can tell them to check or replace (or check myself if I end up having to fix it)? What would cause a random misfire that doesn't consistently happen on the same cyl every time? On a BMW, misfires are 90% of the time caused by an ignition coil, or the coil boot (part between coil and plug, effectively the "spark plug wire", although only a couple inches long). So what am I dealing with? If it was a bent valve, or compression issue, it would be a hard skip that happened every time that cyl fired, not something random, correct?
Only wish I had some Honda experience, but I'm a BMW tech, not Honda. But, an engine is an engine. Please help, or give any info you know. If any of you are on bimmerforums, you know I'm on there all the time lending my expertise. Thanks.
#2
Rachel Bilson
Join Date: Oct 2005
Location: South Bend/Walkerton, Ind
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Bad Gas?
90k is about when the timing belt needs to be replaced
My prelude would miss every now and then, and then my timing belt broke...see if the adjustment will fix it if not..take it somewhere else
90k is about when the timing belt needs to be replaced
My prelude would miss every now and then, and then my timing belt broke...see if the adjustment will fix it if not..take it somewhere else
#6
I
Join Date: Jan 2001
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Fuel, air, spark are the 3 things needed...so you're not getting something there.
Most of the misfire problems I have encountered have been ignition related. Coil, igniter, plugs, wires, etc. Another problem could be the ECU...but that is more rare.
All honda engines that I know of require a valve adjustment.
Try replacing the fuel filter...new tank of gas...etc. Cover the bases, you know what to do.
Most of the misfire problems I have encountered have been ignition related. Coil, igniter, plugs, wires, etc. Another problem could be the ECU...but that is more rare.
All honda engines that I know of require a valve adjustment.
Try replacing the fuel filter...new tank of gas...etc. Cover the bases, you know what to do.
#7
Sounds like you might have blown your valves
Not sure if you are still having the problem or if you got it resolved, but I had the identical problem you described and all you need to do, is to pressure check the cylinders. You might have a number of bent valve stems.
Reason: Down shifting, and accidently going above red line will blow your valves. The S2K are known for this problem and only $2500 later after a valve job my mis-firings disappeared.
If it was something else you are probably really lucky.
Reason: Down shifting, and accidently going above red line will blow your valves. The S2K are known for this problem and only $2500 later after a valve job my mis-firings disappeared.
If it was something else you are probably really lucky.