Spark plug tab pressed in, this can't be good |
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Spark plug tab pressed in, this can't be good |
blitZ |
Jun 7 2006, 07:15 PM
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#1
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Beer please... Group: Members Posts: 2,223 Joined: 31-August 05 From: Lawrenceville, GA Member No.: 4,719 Region Association: South East States |
I started a thread this morning regarding my car starting to clatter and running rough. This evening I put it up on jack stands and popped off the valve covers, everything looks fine. Started the engine and removed the plug wires until I found one which made no difference when I pulled it. I took out the plug and it appears the metal tab was pushed down on the electrode. What the heck is causing this? Is the piston smacking it? I gapped the plug and it runs fine. Any idea of the cause?
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bd1308 |
Jun 7 2006, 07:19 PM
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#2
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Sir Post-a-lot Group: Members Posts: 8,020 Joined: 24-January 05 From: Louisville,KY Member No.: 3,501 |
valve dropped...clattering isnt good at all.
(IMG:style_emoticons/default/WTF.gif) is wrong with these engines...its like five in three months?? b |
Mueller |
Jun 7 2006, 07:38 PM
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#3
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914 Freak! Group: Members Posts: 17,146 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None |
valve dropped...clattering isnt good at all. (IMG:style_emoticons/default/WTF.gif) is wrong with these engines...its like five in three months?? b let's see...the cars are 30 YEARS OLD and being bought and abused by people that think they are like Hondas?!?!?!? |
Aaron Cox |
Jun 7 2006, 07:40 PM
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#4
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Professional Lawn Dart Group: Retired Admin Posts: 24,541 Joined: 1-February 03 From: OC Member No.: 219 Region Association: Southern California |
valve dropped...clattering isnt good at all. (IMG:style_emoticons/default/WTF.gif) is wrong with these engines...its like five in three months?? b let's see...the cars are 30 YEARS OLD and being bought and abused by people that think they are like Hondas?!?!?!? Mueller is having a BBQ,.... roasted britt for dinner LOL (IMG:style_emoticons/default/chowtime.gif) |
Twystd1 |
Jun 7 2006, 07:49 PM
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#5
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You don't want to know... really..... Group: Members Posts: 2,514 Joined: 12-September 04 From: Newport Beach, California Member No.: 2,743 |
Maybe you just got lucky and ate a washer or something. And it passed out the exhaust. (happened to me a couple "O" times on V8s)
If you didn't eat a seat. You might have eaten something that was loose in the carbs or injection system. (check for loose induction stuff) If the engine now runs fine. And doesn't make any nefarious noises....... You are a very, very lucky man...... Indeed...... Twystd1 |
Mark Henry |
Jun 7 2006, 07:51 PM
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#6
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
Over heating is the number one cause of dropped seats. I bet the cyl. fins and shrouding is just full of crap.
Do a valve adjustment before you run it again...one will be way out of whack.... |
bd1308 |
Jun 7 2006, 07:53 PM
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#7
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Sir Post-a-lot Group: Members Posts: 8,020 Joined: 24-January 05 From: Louisville,KY Member No.: 3,501 |
Mike you havent met me, seen me or probably havent actually read into anything about me.
I drive a 1974 Porsche 914, with a 1.7L engine. I cruise, not race (why bother) and couldnt be happier. If I wanted a Hondah, I woudl get one... b |
Mueller |
Jun 7 2006, 07:58 PM
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#8
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914 Freak! Group: Members Posts: 17,146 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None |
Mike you havent met me, seen me or probably havent actually read into anything about me. I drive a 1974 Porsche 914, with a 1.7L engine. I cruise, not race (why bother) and couldnt be happier. If I wanted a Hondah, I woudl get one... b that was not an attack on you, I'm just stating my opinion, which is based on some facts, the cars are 30 years old, motor failures are going to happen more and more.....there is nothing "wrong" with the motors except for age and use and some abuse....expect to see more engine failures both with the /4's and the /6's as time goes on.... |
bd1308 |
Jun 7 2006, 08:00 PM
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#9
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Sir Post-a-lot Group: Members Posts: 8,020 Joined: 24-January 05 From: Louisville,KY Member No.: 3,501 |
Initially I thought it was a general statement...
we're cool. I see this now, I guess alot of people just run the crap out of these engines 20+ years ago and now the OE engines are starting to fail? Global Warming maybe? b |
blitZ |
Jun 7 2006, 08:06 PM
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#10
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Beer please... Group: Members Posts: 2,223 Joined: 31-August 05 From: Lawrenceville, GA Member No.: 4,719 Region Association: South East States |
Thanks for the input, I'll do an adjustment and see what happens. Is there anyway to determine if the valve seat is the culprit without removing the heads?
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Mueller |
Jun 7 2006, 08:08 PM
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#11
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914 Freak! Group: Members Posts: 17,146 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None |
Thanks for the input, I'll do an adjustment and see what happens. Is there anyway to determine if the valve seat is the culprit without removing the heads? you might be able to remove a valve cover and compare the height of the valves as you turn the motor over.... |
Mark Henry |
Jun 7 2006, 08:15 PM
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#12
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
If one valve stem (valve adustment) is sitting way in (seat is out sitting crooked in it's bore) or is sitting way out (sunk into its bore) you have seat problems. Sometimes this doesn't work as the seat can be sitting in its bore but still be loose.
But the spark plug is a classic sign of seat problems. |
SLITS |
Jun 7 2006, 08:17 PM
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#13
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"This Utah shit is HARSH!" Group: Benefactors Posts: 13,602 Joined: 22-February 04 From: SoCal Mountains ... Member No.: 1,696 Region Association: None |
There is prolly some ways:
1.) If the suspect valve is very loose, the seat could have cocked and is holding the valve open. This would case a misfire on that cylinder (won't build compression). 2.) If one valve is very tight, the seat is pulling into the head (under spring pressure). If it can be adjusted to tolerance, it should tighten up rather rapidly. Worst case scenerio is that you can't get any adjustment at all. 3.) I can't see with the configuration of the valves and combustion chamber how a valve could hit the spark plug. I could see the seat coming out and possibly hitting it, but then it would misfire on that cylinder. 4.) And what Muller said Edit*** Are the electrodes bridged? 0.28 isn't all that much and a piece of carbon coming off the combustion chamber can bridge the electrode / possibly bend the tang. |
jimtab |
Jun 7 2006, 08:54 PM
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#14
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Advanced Member Group: Members Posts: 3,477 Joined: 5-January 03 From: Pacifica, California Member No.: 91 Region Association: Northern California |
Initially I thought it was a general statement... we're cool. I see this now, I guess alot of people just run the crap out of these engines 20+ years ago and now the OE engines are starting to fail? Global Warming maybe? b Personally, I blame the insurgency..................bastards........ (IMG:style_emoticons/default/biggrin.gif) |
blitZ |
Jun 8 2006, 05:16 AM
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#15
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Beer please... Group: Members Posts: 2,223 Joined: 31-August 05 From: Lawrenceville, GA Member No.: 4,719 Region Association: South East States |
I think I might pull the intake runner off on that side, might be able to get a peek at what's going on in the cylinder.
Thanks again. |
pfierb |
Jun 8 2006, 05:48 AM
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#16
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oldest member Group: Members Posts: 606 Joined: 1-May 05 From: The sign of good government in Connecticut is to keep raising taxes Member No.: 4,008 |
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Joe Ricard |
Jun 8 2006, 09:29 AM
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#17
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CUMONIWANNARACEU Group: Members Posts: 6,811 Joined: 5-January 03 From: Gautier, MS Member No.: 92 |
Nope, it's Britt's fault.
I GOT PROOF............. |
Elliot_Cannon |
Jun 8 2006, 09:38 AM
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#18
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Senior Member Group: Retired Members Posts: 1,922 Joined: 26-March 03 From: Orange County Ca Member No.: 480 Region Association: None |
Could be a little piece of chop stick? Just a thought. Not necessarily a good one but a thought none the less. (IMG:style_emoticons/default/biggrin.gif)
Elliot (semi retired) |
drewvw |
Jun 8 2006, 09:42 AM
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#19
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new england car guy Group: Members Posts: 1,631 Joined: 24-February 06 From: Boston, MA Member No.: 5,630 Region Association: North East States |
Britt, I'm with ya bud. I am a country cruiser myself. I'd love to vintage race, but who has the cash!! I don't know how you guys do it..... (IMG:style_emoticons/default/beerchug.gif) |
Dave_Darling |
Jun 8 2006, 02:41 PM
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#20
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914 Idiot Group: Members Posts: 14,991 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California |
A compression test will tell you if you have a dropped seat. I had one that popped in and out of the head (while I was driving!!) so a check of the valve clearances didn't really tell me anything. A compression test showed total leak-down (0 PSI!) on that one cylinder. The starter-cranking pattern was also very uneven; it sounded like "RR-RR-RR-..-RR-RR-RR-.."
Try a compression test. If you get one cylinder reading very low, you'll know you need to pull the heads. --DD |
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