| Go back to previous topic | | Forum name | Performance/Engine | | Topic subject | bent valve question - really need advice | | Topic URL | https://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=80227 |
80227, bent valve question - really need advice Posted by CodedRed, Sep-07-04 04:51 AM
I'd really appreciate any advice anyone can give on this. I recently did the headgasket on my '95 nt. Many lessons were learned, some the hard way.
But anyways...here's what happened.
When I first set the timing, there were painted marks on the gears that aligned with the dowels on the cams. So my dumb ass set these two marks facing each other. I knew the right marks to go by, and had intentions of doing it, but I guess I was just rushing and didn't do it. Lesson learned.
I tried to crank it over by hand, it was VERY hard to do - spark plugs were still in. Removed them, and turned the crank by hand 2 full revolutions. Turned pretty easy, no real sign that stands out in my mind of hitting valves. Checked the timing marks, it looked to be perfect to me.
Got the car back together and cranked it over. Of course it didn't start, and I realized what I had done. So I tore the belt back off and reset the timing the correct way this time.
Now, it runs, but it runs VEEEERY rough. Idle is horrible, blue smoke out the exhaust from burnt oil, and severely lacks power.
So the main question now is, if the timing is off a tooth - would it run that bad? What are the odds I bent valves from the first (incorrect) timing setup? In all reality - if I did bend them, it shouldn't even run, correct?
What can I do next to check the situation?
Thanks for any help at all!
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80228, RE: bent valve question - really need advice Posted by KillemAll, Sep-07-04 05:58 AM
even one tooth can cause a very screwed up idle. Redo your timing, and see how that works out. i highly doubt you bent a valve, did you hear any metal clanking?
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80229, RE: bent valve question - really need advice Posted by admin2, Sep-07-04 06:16 AM
Do a compression test before you go tearing into things. Bent valves will give you very low compression in at least one cylinder.
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80233, RE: bent valve question - really need advice Posted by CodedRed, Sep-07-04 06:47 AM
I'll do a compression check tonight and see what the figures are then. There's no sounds that would leave me to believe a valve broke, or anything rattling around in there.
Compression should be 180-ish, right?
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80299, RE: bent valve question - really need advice Posted by OldGuy, Sep-08-04 12:38 PM
170-225 no more than a 25% difference between the cylinders.
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80326, RE: bent valve question - really need advice Posted by Super20G, Sep-09-04 02:40 AM
well, how were your results?
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80362, RE: bent valve question - really need advice Posted by CodedRed, Sep-09-04 02:13 PM
I'll have it done this weekend at the latest and will post here with the results. I appreciate the follow-up and info guys.
Unfortunately, I got tied up at work most of this week and couldn't get it done, been crazy busy. :(
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80386, RE: bent valve question - really need advice Posted by ConceptIllusions, Sep-09-04 07:38 PM
Blue smoke means oil burnin .. could be the rings or valve seals
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80411, RE: bent valve question - really need advice Posted by Star Turbo Talon, Sep-10-04 12:08 PM
If your compression is good, a few marks off will cause a real lopey idle. should not get blue smoke. Do a compression check, leak down test and post the results. You didnt get a lot of oil in the cylinders when you removed the head did you?
Terry
96 Eagle talon ESI Greddy header - Greddy exhaust
97 Eclipse Star Stage II - Boost/oil/EGT gauges - 3" custom DP/Apexi N1 3" exhaust - SFMU/return line - Apexi SAFC - Stage 2 6 puck Sprung hub MIBA clutch - Shortened shifter - Koni Yellows w/eibach prokit - Stillen Fr/Rr swaybars - ceramic intake - DEI Keyless entry alarm - Niche 17" Shoks
Waiting to be installed: HKS EVC IV, 450 Turbo injectors, GSX Front brakes (need rotors)
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80416, RE: bent valve question - really need advice Posted by CodedRed, Sep-10-04 03:33 PM
I'm doing the compression test tomorrow, I don't know anyone with a leakdown tester, so I may have to bring it to a local shop to have that done. I didn't get a lot of oil in the cylinders with the head off, but there was a bit. Kept it pretty clean for the most part, and vacuumed it out with a shop vac before putting the head back on.
I'll post results. That's for the additional info!
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80435, RE: bent valve question - really need advice Posted by Star Turbo Talon, Sep-11-04 04:21 AM
Leakdown test is not a special tester. Depending on the type of compression tester you have.....use the adapter for the compression testor, remove the valve core in the tester adapter. The adapter has a fitting that a air hose will attach to with the gauge removed. use the aircompressor filled with air to fill the combustion chamber on the compression stroke.
Listen for air comming out the exhaust, intake, or oil dipstick/valve cover. In a perfect world you will have no leakage but a tiny bit is ok past the rings (remember they are dry and work with oil.) you can remove the airhose and adapter, squirt oil into the cylinder and retest. Leakage should almost be none. If a valve is bent you will hear either exhaust or intake. it will be obvious.
Terry
96 Eagle talon ESI Greddy header - Greddy exhaust
97 Eclipse Star Stage II - Boost/oil/EGT gauges - 3" custom DP/Apexi N1 3" exhaust - SFMU/return line - Apexi SAFC - Stage 2 6 puck Sprung hub MIBA clutch - Shortened shifter - Koni Yellows w/eibach prokit - Stillen Fr/Rr swaybars - ceramic intake - DEI Keyless entry alarm - Niche 17" Shoks
Waiting to be installed: HKS EVC IV, 450 Turbo injectors, GSX Front brakes (need rotors)
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80966, RE: bent valve question - really need advice Posted by CodedRed, Sep-24-04 09:34 AM
When doing the above with the air compressor, the piston you are checking should be at TDC only so the valves are closed, correct?
Compression results are that cylinder #2 has no compression at all. The other 3 are fine, I finally got the time to get this checked out.
I'm going to check that the lifters are ok, since they were all used lifters on the head I installed. At least I can do that with the head still on the car.
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80967, RE: bent valve question - really need advice Posted by ughhhead, Sep-24-04 11:25 AM
i believe that is correct.
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81785, RE: bent valve question - really need advice Posted by 2point4, Oct-15-04 04:58 PM
I think you should go ahead and yank the 2.4 from that stratus and go for the swap!! laterzzz...chris
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82064, RE: bent valve question - really need advice Posted by CodedRed, Oct-21-04 02:52 PM
I'm considering it, seeing as I'm building another 2.4 block for my stratus right now.
BTW - thanks to everyone for the help. Leakdown test showed exhaust valves were bent in the #2, and #3 cylinder. Head will be back on this weekend.
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