92 Q rocker arm fell off-ideas?

Post by **dreadedboost** » Sat Sep 24, 2005 1:49 pm

I own a 92 Q and a while ago i was sitting at a stoplight and the idle fell to like 200 rpms and it ran terrible. Well it ran but had a very loud tap in the pass. side head so I took the valve cover off and on #8 cyl. the front intake rocker arm had fell off and was laying next to the exhaust cam. I have never heard of this happening before and I was wondering if anybody has any thought as to why this would happen. Could the hydraulic lifter could have failed and allowed some it to just fall when the cam lobe lifter the rocker? zach

Post by **elwesso** » Sat Sep 24, 2005 2:54 pm

Most likely your guides failed, IMO and it sent a valve upward!!

Time to part out the car or put a new engine in!!!!

Post by **dreadedboost** » Sat Sep 24, 2005 3:22 pm

elwesso wrote:Most likely your guides failed, IMO and it sent a valve upward!!

Time to part out the car or put a new engine in!!!!

what do you mean sent a valve upward?

Post by **911/Q45** » Sat Sep 24, 2005 5:11 pm

Overhead cam engines don't have rocker arms.

Post by **maxnix** » Sat Sep 24, 2005 7:47 pm

911/Q45 wrote:Overhead cam engines don't have rocker arms.

Way too technical!

Post by **dreadedboost** » Sat Sep 24, 2005 7:49 pm

what do you call them then smart guy? cuz i dont know and am asking for help. and back on topic what does "sent a valve upward" mean ? anyways if nobody wants to help just say cuz this aint getting me anywhere.
Modified by dreadedboost at 7:05 AM 9/25/2005

Post by **FarFetched** » Sat Sep 24, 2005 8:37 pm

did you see a broken stud or something in that regard?Is it sheared or got loose and fell off?normally cam guides rocker arm thus pushing lifter and so on. Check it over carfuly. check timing.Cheers!

Post by **midnightsliding** » Sat Sep 24, 2005 10:17 pm

911/Q45 wrote:Overhead cam engines don't have rocker arms.

the SR20det has rocker arms, and its a DOHC.

Post by **Jeff Williams** » Sun Sep 25, 2005 2:59 am

I believe they do have rocker arms. See the picture below of Layla's head:

Post by **maxnix** » Sun Sep 25, 2005 5:07 am

Technically, they are cam followers that work in conjuction with the hydraulic lash adjusters. There are no pushrods to activate them.

Post by **911/Q45** » Sun Sep 25, 2005 7:05 am

If you post a picture maybe we can figure out what you're describing.

Post by **Q451990** » Sun Sep 25, 2005 7:52 am

They're called "rocker arms" in the FSM, so that's good enough for me. FSM also says that the HLA needs to be bled if there's more than 1mm movement when you push on it... might compare it with others.

Typically valve damage occurs on the left head during a guide failure, but nothing is impossible. I would put it back together and then check for comrpession (with rocker cover off just turning engine over with starter) to diagnose a bent valve...

Elwesso's theory about "sent a valve upward" means that the engine was out of time (due to guide failure and chain slipping) so the piston hit the valve (it's an interference engine) which would "sent it upward" and usually bend it.

Heath

Modified by Q451990 at 2:05 PM 9/25/2005

Post by **maxnix** » Sun Sep 25, 2005 9:13 am

Q451990 wrote:They're called "rocker arms" in the FSM, so that's good enough for me. FSM also says that the HLA needs to be bled if there's more than 1mm movement when you push on it... might compare it with others.

Yes they are! Probably for American technician's benenfit.

HLA adjustment is very specific in that they don't self purge. Must be purged, kept oiled and vertical prior to installation.

Post by **3rd Q** » Sun Sep 25, 2005 7:21 pm

Anyone know if you can purge an HLA while it's installed in the head? Read the procedure in the FSM, but don't know if I can get to it under the cam to purge while installed. Not up for pulling the cams myself. My '90 has a slight HLA ticking still ofter multiple BG Quickclean flushes. It is minimal, but runs so well otherwise that it bugs me. I'll be pulling the VCs at some point to re-seal and am hoping I can make sure the HLAs on that cylinder are fully pumped up.

Thanks for the input.

Paul

Post by **911/Q45** » Mon Sep 26, 2005 5:32 am

Have you checked your oil pressure with a mechanical gauge? I would guess they tick due to low pressure and replacement won't fix the problem.

Post by **dreadedboost** » Mon Sep 26, 2005 10:34 am

Well I took a closer look this time and noticed that the valve that the "rocker" fell off of is slightly compressed so I'm guessing that the guide is done? I am guessing this also meant it was out of time and has probably bent a valve-thus causing the tapping noise.

Post by **Jeff Williams** » Mon Sep 26, 2005 12:18 pm

Not good news, my friend. Pull the front cover off, and see what the chains and guides look like. You might get away with a couple new valves, a chain and guide set, and maybe an oil pump depending on the amount of running the engine did after it jumped time. Might as well replace the knock sensors and harness and all under-plenum hoses while you are in there.

Hmmmm...that JDM enigne is starting to sound better already. At least there, all you have to replace is the guides, maybe.

Do some more thread searching.

92 Q rocker arm fell off-ideas?

92 Q rocker arm fell off-ideas?

Re: 92 Q rocker arm fell off-ideas? (dreadedboost)

Re: 92 Q rocker arm fell off-ideas? (elwesso)

Re: (911/Q45)

Re: (dreadedboost)

Re: (911/Q45)

Re: (midnightsliding)

Re: (Jeff Williams)

Re: (Q451990)

Re: (maxnix)

Re: (dreadedboost)

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