Valve Gapping at 268.7K (pics)

[sdpatt]

Today I performed the 5th valve gapping service on my own car and was pleasantly surprised with the condition of the valve train components. I found only 1 gap out of spec and 18 of 24 gaps were at the nominal gap or one feeler gauge step below. I replaced all 24 shims to provide a new surface for the very healthy looking cam lobes to press against.

I also removed the fuel rails and injectors to replace the seals between the injectors and the head. I had found them to be very hard and brittle when I removed the fuel rails at 225,000 miles to replace the knock sensor. I took this opportunity to add O-rings to the valve cover bolt seals to slow the oil leaks from the bolts. The spark plugs and wires were also replaced at this service.

Investigating a strange noise that resonated at 3,200 rpm, I inspected the timing chain tensioners to ensure there was some life left in the rubbing blocks. I found some slack in the rear bank chain. I then removed the tensioner (not free from the head) and found the spring loaded piston to have been jammed. It popped free and I reinstalled the tensioner. The front and rear tensioner blocks had about half the block thickness still remaining.

After starting the engine and taking if for a test drive, I found the 3,200 rpm noise to be missing. I believe that the loose rear bank timing chain was oscillating at that rev range. I'm glad I perfromed this service when I did.

You can see a few of the images that I uploaded to my Photoisland account by clicking on the link here -> 268k Valve Gapping and entering the guest password: 268kgap.

<small>[ December 22, 2002, 12:49 AM: Message edited by: sdpatt ]</small>

 

[RTStabler51]

I think all of us are evnious of you.

BTW are you on the original set of injectors??

And any plans for WHEN you hit the 300k mark? beer boink thumbs_u

 

[sdpatt]

The engine is all original except for the normal maintenance items: plugs, wires, water pump, seals, sensors, etc. The fuel injectors are original and apparently still quite functional. Maintenance, maintenance, maintenance. I replace what wears out before it causes catastrophic problems. I had planned to replace the connecting rod bearings this Christmas, but I think I may wait a bit longer since I have no evidence of rod knock. I was going to do it soon because of that resonant noise at 3,200 rpm, but found the cause to be in the timing chain tensioner.

 

[rendyx]

That's really impressive how well you take car of your SHO. I'm planning my virst valve lash this winter or spring.

 

[shojuan]

Everything's so very clean. Congratulations for achieving this milestone; a reward for taking pride in ownership since day one! thumbs_u But for godsakes, get yourself an HP calculator man!

Rick

 

[shodazzl]

Thats the amount of miles I'm sure everyone wants to reach with their shos. Its the problem that you encountered that would have us really baffeled and crazy enough to get rid of our sho. Nice job.

 

[luigisho]

IS that tensioner likley to jamb again? Is it a spring issue or just seating off center?

 

[Yamaha V6]

Personally Scott, at the point you found something wrong with the tensioner, I'd have probably replaced it, especially if it's original.

However, since you're in there like every other month (it seems ), you'll have no problem replacing it when the time comes.

For the novice, if you find something wrong, it's better to replace it the first time, than open it up again (or pay someone else to).

Keep that nice Gen 1 on the road, Mr. Patterson! We're all rooting for 300,000+!

 

[V6&V8SHO]

Hey Scott can you move to Illinois? thumbs_u thumbs_u thumbs_u thumbs_u

 

[DavidT]

ok Scott, that tensioner has me worried. Hears what I'll do... I'll give you top dollar for your sho to take that time bomb off your hands
With the hi mileage, I figure $2500 is MORE than fair... thumbs_u

 

[sdpatt]

shojuan:
But for godsakes, get yourself an HP calculator man!
Rick

How funny that you should notice that. I normally use an HP-11C for my calculatons at home, but I don't want to risk it in the garage. I use a freebie from a former employer (Texas Utilities - back when I was a nuclear engineer) that is all plastic, solar powered and can easily handle the garage grunge (in its Zip-Loc bag).

 

[DavidT]

ok, seriously though, the unusual noise you heard... did you hear it at idle, was it LOUD? Did it change with the rpms? Was it nasty sounding? Or could you barely hear it?

 

[RTStabler51]

eek! So WTF do you do now?? We have one (that i know of, I know there is many more) running around, and OMG, he's stinky, and reminds you of a crack head...we joke and say he's gonna be the next unibomber.......

sdpatt:

shojuan:
But for godsakes, get yourself an HP calculator man!
Rick

back when I was a nuclear engineer)

 

[fricker66]

Scott,
You should know that you and your car are quite popular as you've already had the maximum number of viewers on your photoisland account. Guess I'll try again later.......

Good to hear all is well at 268k. I'm getting ready to hit 90k during our Christmas travels and am thinking that's quite a few miles. Guess not......

 

[sdpatt]

RTStabler51:
eek! So WTF do you do now?? We have one (that i know of, I know there is many more) running around, and OMG, he's stinky, and reminds you of a crack head...we joke and say he's gonna be the next unibomber.......

Originally posted by sdpatt:
back when I was a nuclear engineer)

I now work for Raytheon writing C++ and Java software and performing system installations and configurations of networks that let our armed forces look at neat pictures of the bad guys. This is much easier than the long hours at an operating nuclear power plant. When at the nuclear plant (Comanche Peak, Glen Rose, TX), I was a reactor engineer and also wrote software to make taking the reactor critical and performing the nuclear physics tests so easy that almost anyone could do it. Yeah, God and my parents gave me a few good brain cells and able hands that I am more than happy to put to work.

Windsurfing is one of the recreations that I enjoy using my hands in. The first picture below was my initial presentation in Windsurfing magazine last year. I was happy with my "square inch of fame" in the bottom left of the page in a nine page article on South Padre Island.

October 2001 issue:

As I was successfully finishing up my valve gap job yesterday, my wife said that I had a new Windsurfing magazine on my desk. After the job was finished (after 9:30pm), I quickly scanned through the magazine and bumped into the spread in the second picture. I thought, "Hey, I have a sail like that" and "That guy's not too young." Then I realized that it was not only MY SAIL, but it was ME! I didn't even recognize myself. The picture is a full page in height and split over two pages on a article about the new gear and the preferred equipment for the different sailing areas. The caption mentions the choices of the South Texas coast sailors, like me. I'm pretty stoked; the SHO's valve train is in great shape and I got another picture published in Windsurfing magazine. Very cool.

January-February 2003 issue:

<small>[ December 22, 2002, 10:53 PM: Message edited by: sdpatt ]</small>

 

[smacd]

Hey Pat, I just checked out the SHO movie - looks great! thumbs_u

 

[shojuan]

sdpatt:

shojuan:
But for godsakes, get yourself an HP calculator man!
Rick

How funny that you should notice that. I normally use an HP-11C for my calculatons at home, but I don't want to risk it in the garage. I use a freebie from a former employer (Texas Utilities - back when I was a nuclear engineer) that is all plastic, solar powered and can easily handle the garage grunge (in its Zip-Loc bag).

Hehe, funny thing about an HP is it doesn't matter how old a model it is, they all work so well that it's not unusual to find a guy still using the same calculator he got in the 70's or 80's. I know that the only way you'll get my HP-28S away from me is when you pry it from my cold, dead fingers. It was a highschool graduation present and 13 years later it's still my preferred tool for numerical calculation. Never once had a desire to get a newer model. What makes me sad is there was a time when I could have picked up a couple of used spares really cheap, but ever since ebay the damn things fetch a small fortune. Oh well, mine will probably outlive my SHO 2 or 3 times over

Rick

 

[RTStabler51]

Raytheon eh? hmmm...I'm gonna have to hit you up for a job in a year or two. I wouldn't mind living out in Texas

sdpatt
I now work for Raytheon writing C++ and Java software and performing system installations and configurations of networks that let our armed forces look at neat pictures of the bad guys.

<small>[ December 23, 2002, 08:29 AM: Message edited by: RTStabler51 ]</small>

 

[Blast7]

268K and still running fine? No way! Don't you know that SHOs are unreliable. wink J/K, congrats on the excellent status of your SHO and kudos to you for actually holding on to the SHO for this long and performing all of the maintenance.

 

[sdpatt]

dkautumna:
ok Scott, that tensioner has me worried. Hear's what I'll do... I'll give you top dollar for your SHO to take that time bomb off your hands [yeah, it may blow in another 1/4 of a million miles or so]
With the hi mileage, I figure $2500 is MORE than fair... thumbs_u

You are right, $2,500 IS more than fair. Even Kelley Blue Book says that my car is only worth $2,365.

The noise is actually still present and sounds more like a solid metallic vibration that resonates at 3,200 rpm and cuts off sharply as the revs rise above that value. I can't hear it from the engine compartment, but in the quiet of the interior, it is apparent. I tried using a metal rod to locate the source of the noise, but I wasn't able to get a definitive point of origin.

The timing belt tensioner may have been fine, it was just that I felt the non-tensioner side of the chain to have a slight bit of slack while I was turning the crank (always CW) during the valve gapping procedure. When I reinstalled the tensioner, the chain was quite snug. There was about half of the tensioners rubbing blocks' thickness remaining even after all these miles. Thankfully.

I will be performing the front end 60K before the end of the holiday break and will see the condition of the timing belt and tensioner pulley. I will also be replacing the camshaft seals, crank seal, CPS, CID sensor and accessory belts. I know the cam seals are leaking and have made some mess that I will be cleaning up to get my engine back to picture grade condition. Pictures to follow.