Finally...guides being changed!

[jefftrexler]

Well I'm finally getting the guides on my '91 Q45 with 168,000 miles on it changed. At the same time the valve covers are being resealed. My mechanic friend took the valve covers and was absolutly astonished. He called me and asked if I was sure this car had 168,000 miles on it. I told him yea and to check the odometer. He told me that I had better get to the shop and look at my engine. So here I am, freaked out and about to crap myself. I drive like a mad man in a borrowed car and get to the shop. I run in the shop (a little winded) and notice that my Q45's hood was closed. This was not a good sign to me. The mechanic pops the hood and shows me a perfectly clean valve trane!!! He said it blew his socks off that after 168,000 miles that this car's valve trane for all intents and purposes was perfect. After laughing it off....(kinda pissed a little)....we joked around a little bit. Everything is scheduled to be finished today, so I'm eager to get my ride back. Here are some pics that I took with my digi cam...

[AZhitman]

Wow! That's great news, Jeff!

Clean the plenum and intake ports as well as the TB while you're at it. Also swap the under-plenum hoses (ALL) and check all injectors and knock sensors...

Is the chain guide the rectangular piece covering part of the chain in the far left of pic #3?p.s. Nice FRAM filter. Have you no shame?

[dougs98Q45]

Talk about a clean engine! Suddenly I feel a little guilty......

[jefftrexler]

Wow! That's great news, Jeff!

Clean the plenum and intake ports as well as the TB while you're at it. Also swap the under-plenum hoses (ALL) and check all injectors and knock sensors...

Is the chain guide the rectangular piece covering part of the chain in the far left of pic #3?p.s. Nice FRAM filter. Have you no shame?

Plenum, ports, and throttle body have already been cleaned. I did those about 4 months ago. The hoses were all replace a year and half ago and the injectors and knock sensors have all be checked and are running strong. Yea....that rectangular piece is one of the guides in pic #3.

Oh...and the FRAM filter was put in by WalMart when they did a Mobile 1 Synthetic oil change. Only cost me $25 for the oil change. I'll be getting a Napa "Gold" filter (same manufacturer as the stock Nissan filters) when this is done. I'm thinkin about tryin Redline Synthetic oil when the guides are finished. Has anyone ever tried this stuff? My mechanic said that its great stuff....better than Mobile 1 and he can get it cheap. So far, I'm happy with the progress.

BTW....the valve cover reseal and guide (and oil chain) replacement is only costing me $300. :pface

[90Q45blue]

Holy crap! That's gotta be some kind of record

[elwesso]

Id like to do my valve covers sometime (maybe with the plenum)...... Do you know how hard it was...... Also, is there anyway to clean things out while your in there......>

[jefftrexler]

Id like to do my valve covers sometime (maybe with the plenum)...... Do you know how hard it was...... Also, is there anyway to clean things out while your in there......>

Well my mechanic said he had one hell of a time taking the valve covers off. He claimed that it was a "PITA" (Pain In The @$$). He said the hardest parts were getting those damned rear bolts o=ff the valve covers.

What do you mean by "clean things out"? Clean what out???

[Q45tech]

Obviously standards are lower than mine. There is a lot of varnish and from the pictures, plus what appears to be some wear on the cam lobes and followers.

I would call this average [to slighttly above average] for mileage.

[elwesso]

I meant by cleaning out all that oil residue off..... It looks like it could be easily removed with some carb cleaner and a rag....

[nuQ]

$300?????????? EITHER IT'S YOUR BROTHER-IN-LAW OR YOU HAVE PICTURES OF HIM AND A DONKEY!!!!!!!LOL

[SOCAL91Q45a]

"There is a lot of varnish and from the pictures, plus what appears to be some wear on the cam lobes and followers."

This could be lessened, or prevented by?

90 day oild changed ... head valve and cam refurb at xxx,000 miles?

[PalmerWMD]

No need to refurb anything, with 3000 miles/90 day oil changes with good oils

Fred...

[jefftrexler]

Well tommorow my car will be finished. The guy who's working on my car is really quite good, but this car is a definatly learning experiance for him. He took out the 2 long guides and for some weird reason they are barely worn!!! Except for a shallow groove along the guide from the chain rubbing against it, it is otherwide perfect. No cracks, no signs of being brittle or any scratches. The new 2-piece guide that replaces it is quite cool because it looks like it will minimize any slap of the chain against the guide itself. The only problem is the original bolt that holds the guide to the block is too short for the revised guides!! It leaves only about 1/8" of thread to go into the block versus the 5/8" of available thread with the original guides. I'll need to goto Beaverton Infiniti (shudder) to get 4 longer bolts. The oil chain was the scarry part. It had about 5/8" play in it. I dunno if this is supposed to be that way....but I'm guessing no. Anyways...here are some pics of the oddly enough new-looking old style guide and how short the bolt ends out being when pushed through the new guide.

Old guide...

Bolt with old guide....

Bolt with new guide....

[DAEDALUS]

Great to hear the oil pan won't be coming off. You didn't get the kit from Joe? It includes the 4 bolts you need. Under constant operation the chain shouldn't touch the guide I don't think. It's probably only when you jump off heavy throttle quickly or hit a large bump that there might be enough slack for them to touch. The oil chains I've seen were all pretty loose. Seems they're looser than what wear alone would explain, yet I also don't think it would stretch that much either. And I doubt the guides could have slipped, but maybe. If you get the chance compare the old and new oil chains' lengths.

[jefftrexler]

Weird thing is...there are no records of the guides ever being replaced. Hmm....I guess I'll just chalk it up to good luck.

[DAEDALUS]

I've seen a Q at around 180k with intact guides. But yeah, there's some luck there.

[texasoil]

The photos show a moderate amount of varnish but no sludge. The guides lasted because the owners did not run it 6-8 K miles between changes. When oil stays in too long, it gets acidic and attackes the plastic in th eguides. Also, gasoline thah has ethanol or high amounts of MTBE can cause the plastic to crack.

The Q45 engine is an extremely durable and well designed peice of art.

Oil is cheap! Hard parts are expensive. 3000 mile changes with major brand 10W40 is a great way to keep it as new.

[natsoundup]

Well, I am still keeping my fingers crossed on the old guides...

1990Q 156k miles.... oil changed every 3k miles or 90 days.

I know many of you think it's foolish....but it's my position --both economic and mechanical--- for now..

[jefftrexler]

Well I get my Q45 back tonight! Its been a week, but its worth the $300. I also got new bolts, a coolant system flush and Valve cover reseal for free because it has taken so long. One little scare when they discovered that they accidently plugged a coolant line into a vaccum line that leads up to the intake plenum. It was caught quickly though. Hydrolock anyone? Wow.....almost had to get a new motor there. Anyways, they are doing the final look overs now before they start it up. I'll keep you guys posted.

[jefftrexler]

Well....I was there when they went to start the engine. Now it did make a little bit of racket, but that was expected. Then there was a thunk sound and it turned itself off. The thunk came from the passenger side of the engine bay. After looking over every hose and wire and running through every sinerio we could think of, we decided to start it again. This time with the MAF sensor unplugged so it wouldn't turn over. Ok, it made the normal RRRR RRR RRRR RRRR sound of an engine starved of fuel makes, and then there was a pop repeated by another pop roughly 5 seconds later. The pop sounded like when you first open a Snapple drink bottle. We stopped and decided that the pop was in time with the engines compression cycle and sounded like it was comming from the front of the engine. After looking through every thing, they tried it one more time....again with the MAF unplugged. The started "RRRRR"ed once and then stopped. It seems like the engine is somehow seized. Now these guys have tripple-checked everything at every step making sure everything was in the right place.....minus that one vaccum hose incident. Anyone have any ideas as to what may be the issue here? The chains never moved from the sprockets, no foreign objects made it into the cylinders or into the valve train, the crank angle sensors are in properly and all plugs are plugged in the proper cylinders. I am at aloss here folks. Please lemme know what you guys think.