Got my intake off - Need some trained eyes for a few ?'s

[40BelowSummer]

Okay so as stated in this thread here I have been trying to find the source of a diesel/ticking noise that has been pretty loud lately. It was suggested it may be the valves or cam chain/tensioner. So lets see if we can find it

After broken sockets, bloody fingers, thrown tools I got my intake off

BTW I really really can't thank anyone here enough for helping me get through this. Anyways...

I took some pics of the chain and cams. So anyone can see if anything looks wrong, to me (untrained eye) I dont see anything that stands out. The chain/tensioner feels nice and tight though

But please I need comments/suggestions in order to find where this noise is coming from (this is good practice for my 60k in a few weeks when I get the right tools) thumb thumb

So please comment on the following pics, I can take more pics too just tell me what I need pics of (while I wait for replies, Ill go take off rear valve cover)

THANK YOU ALL

Cam chain
---------------

<small>[ February 23, 2004, 08:47 PM: Message edited by: AutoSHO ]</small>

 

[Machspeed]

Is that pennzoil?

 

[40BelowSummer]

Valve/Cams

 

[DavidT]

hey, that looks like my old 90 sho
It had the deisel sound you talk about... it would make me CRINGE!
Anyways, did you check under the REAR cam caver as well? That is where I pinpointed my noise (with my ear only). On mine, best I could tell (I am a novice, except for what I've learned through the forum!), the chain had maybe a half link to a link slack in it. If I moved the cam back and forth (slightly), I could see the bit of slack. Too me, it didn't "look" like THAT could cause the skin raising racket that I heard at times. I just buttoned everything back up... I guess I am a quitter pcorn Besides, I couldn't get a step by step guide by anybody when I had it apart. Hopefully you will have better luck.
Good luck with yours!

 

[40BelowSummer]

FOR SHO:
Is that pennzoil?

not sure, havent put oil in yet (almost time for a change) that would be from prev owner

just curious, why do you ask?

 

[AutoSHO]

In the very last picture the chain looks a bit slack. Is that the case? Does it have any slack or is it held very tense? that tensioner does not show much wear, which leads me to believe it may not be doing its job.

 

[DHMag]

gotta love the gold plating on the internals eh ?

check the rear cam tensioner. i just tore apart a motor that was missing the "plastic." you might have to remove the tensioner to look. if its not there, it will allow enough slack in the chain to tap against the head/valve cover. too much slack and youll start jumping time.

 

[40BelowSummer]

guys i seriously appreciate the quick replies. thanks

well im off to take rear cover off thumb

bring some pics in a few... beer

 

[revhardSHO]

Supposedly Pennzoil will Carmel color your internals (even with frequent oil changes; however this is not the case).

Interestingly enough, infrequent, high-mileage interval oil changes will have the same EXACT effect using just about any brand of oil (not just Pennzoil). This is a given.

Many times people will use Pennzoil as the “scapegoat”, when in fact the motor just needs more frequent oil changes, regardless of what brand oil is used.

I own a 90' sho w/ 130K. I am the second owner. The previous owner used Pennzoil till the day I bought it. Regular oil changes every 3-4K. The heads look almost brand new, exactly like Scotts 283K Castro GTX fed sho. That’s proof enough for me that Pennzoil doesn’t do what people say it does.

Im not trying to open a can of worms hear, or get anyone mad. This is just my take on the whole Pennzoil thing. I’m playing the devils advocate, if you will.

*Please note my personal preference is NOT Pennzoil. I don’t use it in any of my SHOs. The 90' doesn’t see it anymore either. This does not mean I have anything against Pennzoil.*

 

[91taurisho]

smithsil:
*Please note my personal preference is NOT Pennzoil. I don’t use it in any of my SHOs. The 90' doesn’t see it anymore either. This does not mean I have anything against Pennzoil.*

If I may say so, I like the little disclaimer...

 

[DHMag]

smithsil:
Supposedly Pennzoil will Carmel color your internals (even with frequent oil changes; however this is not the case).

Interestingly enough, infrequent, high-mileage interval oil changes will have the same EXACT effect using just about any brand of oil (not just Pennzoil). This is a given.

Many times people will use Pennzoil as the “scapegoat”, when in fact the motor just needs more frequent oil changes, regardless of what brand oil is used.

I own a 90' sho w/ 130K. I am the second owner. The previous owner used Pennzoil till the day I bought it. Regular oil changes every 3-4K. The heads look almost brand new, exactly like Scotts 283K Castro GTX fed sho. That’s proof enough for me that Pennzoil doesn’t do what people say it does.

Im not trying to open a can of worms hear, or get anyone mad. This is just my take on the whole Pennzoil thing. I’m playing the devils advocate, if you will.

*Please note my personal preference is NOT Pennzoil. I don’t use it in any of my SHOs. The 90' doesn’t see it anymore either. This does not mean I have anything against Pennzoil.*

not to add to this reply, but using it as a reference...

what makes the inside of the crankcase turn colors is, like stated, infrequent oil changes or neglected oil changes. when the oil gets used up...thermal viscosity, lubricating features et al, the residue it leaves behind is what you see on the pics above. with the engine being warm, the "tar" will soak into the block, heads, cams, making it near impossible to remove without a lot of elbow grease.

with an engine disassembled, i could sit there and waste 20 cans of Berrymans B-12 to get it almost clean, or i can use a few dabs of aircraft paint stripper and get it completely clean. this is off topic, but just thought id kinda try and explain why the internals change colors on some engines over time .

 

[aaronsbiza]

What exactly does this diesil sound, sound like?

I have been hearing some weird noises near the rear of the cams. Almost like a groaning rubber sound. Also I have been hearing, mostly upon acceleration, a very soft very fast ticking type sound, but not like a single valve ticking, more like a whoosh of ticking..?

It's hard to describe a sound in words. shrug

 

[DHMag]

when dieseling occurs in a gasoline operated engine, it is actually the engine turned opposite its intended rotation. more evident when the vehicles ignition is cut off, the engines almost dies, then starts dieseling. happens because 2 cylinders stopped just short or right at TDC on compression stroke. to me, it is incorrect to say you hear your engine dieseling while its running.

i had a ticking noise in my engine prior to 60K, found that the PS torque dampner mount on the engine was minus one bolt and the other was loose. other common reasonings for ticking is valve lash (whether it be too narrow or too wide of an adjustment), and as covered by this thread, slack cam chains. another possibility is that you are hearing the injector pulses, which make a ticking sound.

 

[AutoSHO]

Dieseling (or Run-On) occurs in older carburated engines that do not shut off fuel to the engine when the key is turned off. Carbon buildup in the combustion chamber gets so hot that it actually ignites the air fuel mixture, even when the spark is no longer present.

<small>[ February 24, 2004, 03:20 PM: Message edited by: AutoSHO ]</small>

 

[DHMag]

AutoSHO:
Dieseling (or Run-On) occurs in older carburated engines that do not shut off fuel to the engine when the key is turned off. Carbon buildup in the combustion chamber gets so hot that it actually ignites the air fuel mixture, even when the spark is no longer present. The engine is not spinning backwards, however.

in my nearly 20 years of working on cars of all makes, models, sizes, and shapes, 90% of the dieseling ive witnessed has proven the engine runs backwards as it diesels.

 

[Off Road SHO]

I agree with DH mag.

You stop a dieseling gas motor car by slowly letting out the clutch in any gear. If it's in any forward gear, your car will lurch backward. If you put it in reverse, your car will jump forward. Try it. I've won many a beer that way.

Tom

 

[40BelowSummer]

it wasnt "dieseling", that is a term. it was a noise similar to a diesel engine.

what do/can shiny scuffs/scratches on the cam mean?

 

[fricker66]

Worn cam lobes, you definitely need to check the valve shims for wear. Depending on how bad the scratches are, you will probably find the shims will have a short life.

 

[40BelowSummer]

Well I do not want to do this again soon, so I am just going to do my top end 60K before I put it back together. My intake gaskets are trashed so I would need new ones anyways so why not do the rest? I can borrow $200 from someone close hopefully..

Intake Gaskets ----$50 (MidwestSHO)
Spark Plugs -----$25 (FPN)
AC Delco Plug Wires------$60 (Midwest SHO)
Valve/ Plug Well Gaskets ------ $72 (Autozone)
------------------------------------------------
$240 Estimated After shipping etc
minus tool rental from someone

The rear valve cover is a %$#&%, I have yet to get it off, I got all the hex screws off/lossened but too much crap in the way to remove it.

Do the rear support brackets need off?

 

[Anthony1238]

i would definitly take off the rear supports... and try to move anything out of the covers way... the rear is a real PITA...not so much getting it off but putting it back on with a new gasket and trying to posistion it correctly and not kink the gaskets... it took me 2 trys and to get it on correctly...i didn't notice i kinked to gasket till i put her back together and added oil and it just draind onto my drive way and Exhaust... that was a fun night...goodluck and don't make the same misktake i did..