How long did your guides last?

[DAEDALUS]

All you 1st-gen Q owners out there, please respond. I'm looking for whatever statistical data can be collected regarding the lifespan of 1st-gen Q45 chain guides. I would like to know year of make, mileage, climate, age at inspection (or date), and whether you lost an engine, had parts in the pan, or had all guides intact. Also, I have mainly heard of the driver's tension-side (straight) guide failing. If any others have failed on your car, let me know too. Thanks!

[PalmerWMD]

-One failure at 104k, car was 6 years old at time (engine total loss), Climate Minnesota.-Other failure at 88k (engine was 7 years old at that time), engine also total loss., Climate GA and MN.

I have had hearsay of a non club one at 66k, Climate unknown.

Fred...

[DAEDALUS]

YEAR: 1990MILEAGE: 209kCLIMATE: Moderate CAAGE: 12 yearsSTATUS: Entire guide (1) in pan (5 pieces)

[LAQ]

i think im on a verge.92 q, 115k, no record of replacement guides as of today,california car, runs like a new car.

[911/Q45]

55K, 90Q, Perfect when replaced, SoCal coast.

[Q451990]

Mine went out in March of 1999 at 120,569 miles. No warning noises, just felt like half of the injectors died at one time. Engine was still running until I turned it off... just backfiring and bouncing a lot.

$2700 later I got it back. Only one very slightly bent valve but they replaced all four on that cylinder. Climate - Atlanta GA until 8/96, then Columbia, SC.

Another one (a 1991 I think) with 77K was there with very severe damage - holes in the piston heads - valves completely sheered off, etc.

I'm not sure which guide failed, but it was on the left side, which I think is typical.

Heath

[LAQ]

does one feel the difference once the guides have been replaced? if so, how?

[texasoil]

IMHO it is not possible to predict how long the chain guides will last before breaking. Sometimes, they fall harmlessly?? into the oil pan or lay around. Other time a peice will jam in the chain/sprocket and cause major engine damage/destruction.

IMHO, the life before disintegration is a strong function of the acidity level in the cranksace fluid (oil). The more frequent the changes, the longer they will last.

However, 7500 mile changes on a 100 mi/day SoCal freeway car is easy service compared to 150 m/wk on a NYC car.

It's a matter of risk tolerance--can you stand losing the car completely (engine damage is usually not economically repairable, have to install used engine for $3500+/)

If not, either sell it of fix it before it breaks. Odds of breaking are ????

[DAEDALUS]

You are absolutely correct about the guides being able to fall harmlessly into the oil pan, or destroying the engine on the way down. I don't know about the affect of acidity on the guides; they're nylon, and the break surfaces indicate brittle fracture at work. Would acidity on the surface of the nylon guides increase brittleness throughout the part? Not as much as temperature cycles, I think, if at all. How permeable is nylon to a weak acid? Regardless, the study is far from worthless. If you had 50 instances of guide failure, and in all cases the guides broke into an average of 7 pieces, and of the 50 cases, 5 ended in timing failure, wouldn't that say a lot? To the first order, it tells me that 10% of guide failures destroy the engine. That's important if you believe, as many do, that guide failure is a question of "when" and not "if".

[Q45tech]

As long a less than 1% failed prior to 6 years or 70k Nissan was happy. Since less than 43,000 engines had the old style guides, my guess is that less than 1,500 engines failed [or we would have heard more about it]..........we have changed less than 15 engines for guide failure plus [5 for rod bearings, 6 overheated] extrapolating our customer base to the world at large say 1% of 90-93Q are serviced by us.......that would be 1000-1200-1400 guide failures or so {?????????}

By now my guess is 20% have been totaled in wrecks something like 8,500 cars. Another 14,000 are sitting waiting for a buyer [various payhere lots/dealers] and maybe 19,000 are still on the road from rolling wrecks to a few pristines.

Reminds me of a last summer story [the same thing usually happens every summer in one form or another]: Ragged out Q we recommended a water pump as it was leaking bad!!! customer declined, we filled the radiator and said good luck, 2 hours later the customer called complaing of overheating told to TOW it back, he DROVE it back, the engine was measured at 500F with IR on arrival ......destroyed!He raised Holy Hell saying we should have FORCED him to change the pump [at gun point????]..........walked around screaming for 2 hours till we called the Police.........sued the Judge laughted him out of court.

We can't force you to be good to your car we just keep a few dead engines and bent parts laying around HOPEING customers get the message -- same with chain guides.

[Qdog]

92Q 113K at replacement no cracks no damage just wear from chain contact. Texasoil: would synthetic oil become less acidic than conventional ? Is type of oil a factor in guide failure ?

[natsoundup]

my 90 Q is now pushing 150k. I got it at 43k....it was originally in Connecticut I think... I am the second owner.

It spent from 93-98 in New Orleans...my wife drove it...oil always changed at 3k miles or 3 months...

From 98-present...I have driven it in Greenville, South Carolina. I go back and forth on getting them done....if it was 1200 dollars I might do it... if it's 17-1800...that puts it not far from what the car is worth alive.

My biggest concern is I get the guides done....and then the a/c goes out and it costs me 1500 dollars...

Tough dilemma.... drive it round trip in a day recently 430 miles... ran nicely.....

I take good care of the car...but am not a fanatic with it.. my next job is getting the bose speakers refurbished for 300 dollars....

I am also a pretty easy driver.... did take it to about 120 the other night on the way home...still had plenty of room to go after that.... but I wasn't on the interstate and didn't need to kill myself.

[paintwgn]

Had the guides done last May, 2002 on my 91Q at 104,000. The old guides, chains and oil tensioner ( I still have the old parts) show no signs of wear or delamination. When the mechanic had the engine torn apart, I was amazed to find the cam lobes looking brand new-no wear at all. I have always used Mobil 1 10W-30 and do oil changes every 4 to 5000 miles with Fram filters. Live in Phila. area.

[bryq45]

My 93 Q has a build date of Dec '92. THe last six digits of my vin are 225021. It may have just barely made the cut off ( if such a 'cut off' date even exists for the new guides).

It has 117,2XX Miles and going strong. I pray that it can last until i graduate next December. The first thing that my engineering buddies that just graduated did was Jump up and waste their money on a Brand new depreciating asset (liability).The first thing im gonna do when i graduate is get the guides done. I already purchased the $500 kit from Scottsdale.

P.S. I have found that the 1st gen Q45 can and should be one of the best cars to own, and I plan to keep mine forever. BUT it is the ABSOLUTE worse car to have while in college.

[Q45tech]

http://www.shef.ac.uk/mecheng/....htmlh ... .html#0020

The above shows the Q engine in their example

[bryq45]

Has anyone compiled a list of tools required to do the timing guide job? (Im willing to try to replace the driver side guide myself, but not the chain).

Also, it would be Great to see a step by step procedure that describes how to do the job without breaking /damaging other stuff in the process. Are there any major pitfalls?

[911/Q45]

Talk nice to Daedalus and he'll set you up. The only semi-special tool I used was a 3/8" drive allen head driver in 4 or 5 mm for those really tight little bolts that hold the guides on the block. Order the guides and make sure they include the longer bolts, then check them for the right size, so you can get the tool before you start work. A dental pick was handy for cleaning the RTV out of all the little grooves! Be sure to replace all the guides, the passenger side is much easier because of the little hook on the tensioner.

[DAEDALUS]

http://www.nissaninfiniticlub....=1632

[DAEDALUS]

Most tools needed are fairly common--ratchets, 8, 10, 12, 14mm sockets, 5mm allen driver (get a driver, don't use an L-shaped wrench!), screwdrivers, etc. The big tools are 30mm (I think) socket for the crankshaft bolt, and a chain wrench and large driver to be able to apply at least 270 ft-lbs of torque. You need to be able to measure that torque too to ensure that you have enough on assembly. A large puller will be needed for the harmonic balancer. Sears has one for about $30 that works. Biggest pitfall is to be very careful with the solid gasket above the cover...if you damage it you'll have a very hard time getting the cover back on without completely destroying the gasket. Replacing a head gasket on a Q is something I'd never want to do.

[MY92Q]

92 Q 133K, to my knowledge org. guides. Have thought about doing it myself and probably will this spring. Owned it for 2.5 years, bought it from a friend who always changed the oil. Car runs great and really want to keep it. An Infiniti mechanic told me off the record he has seen only 2 or 3 guide failures in his 12 years with Infiniti, he said don't worry about it. I love the car so I'm still going to do them.

[firstq]

92Q, bought at 95K, changed guides @101K - tech found 3 guide pieces in the oil pan.

The car has always been in Arizona.

[QShip]

Mine were done at 35k.

[DougQ45]

Daedalus: 1991 Q had 177,000 when guides were replaced (remember it was about 110 degrees that day!!), and they were in one piece, but brittle. Second 90 Q had 90,000 and were also in one piece. Was hoping to find them in much worse shape so the sense of accomplishment would be greater, but post replacement sense of security was a good offset.

[misterQ]

I just ordered a set of guides and tensioners for my 91Q with 119k. I plan on doing the job myself 2 weeks from now. Just one question. Did Infinity change the legnth of the guide bolts for the upgraded guides? I have downloaded Daedalus's thread on instuctions for the job(Great help). The service manual says pull the engine. Not! Just gotta stock up the beer cooler in the shop and I,m ready to roll.

[911/Q45]

Yes, you need new bolts for the guides(longer). Watch the beer, ref. AZhitman's rear struts!

[90Q45blue]

Quote »P.S. I have found that the 1st gen Q45 can and should be one of the best cars to own, and I plan to keep mine forever. BUT it is the ABSOLUTE worse car to have while in college.[/quote]

I completely agree. I'm in my 2nd year now and while I love this car to death, the cost is just killin me. The way I always look at it and the reason why I can never get rid of her is this: it is ALWAYS cheaper for me to fix my Q than it would be to purchase another car this nice. After I tell myself that, there goes the money

But I wouldn't trade her for a Porsche....well....maybe a Carrera GT2.

Nick:)

[bryq45]

Quote » it is ALWAYS cheaper for me to fix my Q than it would be to purchase another car this nice.[/quote]

Amen.

[Q45tech]

You sure can't get much of a car for $300 a month with nothing down.And most Q don't require $3600 per year: year in year out over 3-4 years.....some do, depends.

The problem we see is people who owe a loan [paid way too much didn't know what they were buying.....as they came from a Civic or such or some Generic uniy] and still have the mainteance cost, insurance, tax/tag, and gasoline........then it's cost them double...$800/mo.

[TnQDrvr]

My guides were replaced at 130K at T-3; were still in very good shape. Southeastern US climate, oil changes every 3K, 90 model purchased in 93 w/27K on odometer.

[greg_atlanta]

My '92 Q guides failed at 130K in Oct. 99 on previous owner (who traded it in). Probably poor maintenance habits.

$6000 dealer repair job and I bought for $9000 in Dec. 99.