Q45 Timing Chain Guide Replacement

[jlgallag]

I own a 1991 Q45 with 59.5K original miles. I have owned the car for about 10 years and I am the second owner. I bought it with 10K miles and have had all required maintenance performed. In the course of owning the car I have done all scheduled maintenance and have had a number of expensive R&R items done. Everything works well and the car is in great shape. Recently I have been seeing quite a bit of correspondence on the net about the timing guide problems related to the 1990-1993 Q45s. My question is related to whether the problem is related more to mileage on the guides or their age. When I questioned the service department at the Infiniti dealer where I have the car serviced they led me to believe that the problem is due to mileage and use and that I should not be concerned about it for quite a while based on the annual mileage that I put on the car, about 5K miles per year. They said it would become more of an issue if I still had the car in another 30K-40K miles. Based on the experiences that you might have, do you agree with the advice I was given about it not being a concern for a few more years? I am not considering getting the guides replaced at the prices that I have seen in a number of Internet postings.

Any advise will be greatly appreciated. Thanks in advance.

jlgallag

[DAEDALUS]

I think both mileage and age affect the life, in addition to temperature. The guides are plastic. Like all plastics, they will get brittle and tend to crack as they age and when temp and stress cycled. The earliest failure that I can recall happened before 50k, though that's obviously well below average. If you want to keep the car, my opinion is that you shouldn't take the chance. I agree you will probably be fine over the next 30k-40k, but why risk it when the cost to fix a broken engine could be $4-$8k? What prices have you been seeing? Have you considered doing them yourself? Welcome to NICO BTW, great car at 60k!

[jlgallag]

Daedalus - Thanks for your quick response, and thanks for the welcome to NICO.

The prices I have been seeing on the Internet have been in the $2.5K to $4K range if the work is done by a dealership depending on whether the chain is also replaced, although I have not priced the work at my local dealer. I have also seen some mention of a <$1.5K price if the work is done by a company in Atlanta, a bit too far out of my normal driving range to consider going there from NY. Are you aware of any recommended places closer to NYC that would do the work for a reasonable price?

If I am relatively safe for the next couple of years or 10K miles I will probably not do the work because I have been considering replacing the car with a preowned 2002 or 2003 Q45 some time in the next year or two.

Thanks again for the help.

jlgallag

[maxnix]

While deferring to Daedalus's expertise, I think even he would agree that timing chain guide failures show no mercy.

They could literally fail the next time you start your car. Or when you are making that critical passing maneuver. How much have you saved when you have a head-on?

The other part to consider is what your car will be worth when you sell it. Without the new guides, if it lasts that long, it will be worth virtually nothing to a knowledgeable buyer as it will be assumed the guides need replacing. Assuming the bigger fool theory is not prudent, in my view. With your low mileage, if you find a competent independent shop, you might come close to breaking even and drive without fear of sudden engine failure in the meantime.

On the other hand, if fluids have not been well maintained, power steering, transmission, radiator, or AC could be in for failure soon. Then you are in a triage situation.

Even mature couples I have spoken to with pristine, low miles 1990-1993 Q45 have generally assumed they would junk the car when the guides failed. A shame, especially with so few 1990s remaining. I find it interesting, despite their maturity, they assume since failure hasn't yet occurred, it won't, at least to them.

In real estate, failure to maintain is also known as wasting an asset.

[paintwgn]

Welcome to NICORecently had my guides done at 104,000 mi. on a '91Q by a very good local shop (Phila. area).I bought the parts myself at the dealership for about $320 and paid the mechanic $1,200. He said it took him 2 days. Fortunately, I have gotten to know the parts manager at the dealer and got a good deal on the parts. Interestingly the old guides, which I kept, showed no signs of delaminating or cracking. It was the first time this particular mechanic had done a guide replacement on an old Q and and he thought the engine was definitely "over-engineered".The Infiniti dealership wanted $2750.00 to do the same job

[greg_atlanta]

Is the transmission original? If so, I wouldn't bother with the guides. Doing the guides is good preventative maintenance if you want to keep the car a long time, but chances are the transmission will fail at some point (they generally fail at 80-100K on an early Q, but of course that varies with age, mileage). I'd hate to see you spend $2-3K on guides and then feel obligated to replace the transmission for $4-5K (dealer price)... and then find out the car is only worth $3-4K, even with low miles.

I'd say keep the oil changed every 3 months regardless of mileage, have the transmission flushed once a year, and enjoy the car for what it's worth. If the time comes to get a new car and the '91 Q is doing fine, you might be able to sell it at a premium if everything is working (and let the next owner do the guides if he/she is aware of issue).

BUT.... make sure you test drive the new Q and see if you LIKE it. One reason a lot of us are long term Q owners is because we can't find anything else we like more!!! Sometimes a few weeks spent test driving new cars can make you fall in love all over again.

Confusing dilemma, huh?

[PalmerWMD]

Gallag:

Much has been written on that subject but I feel the combination of age, heat/cold cycles and oil change habits contribute very much to teh problem.I had guides fail twice on me (109k and 85k).

If you have a nice Q do the guides what it's "value" on the market is means <nothing> because the average Q will not be maintaned nearly as well and therefore function not as well as a Q typical to a NICO clubmember.

If I was you I would get the contact info from paintwagon philly is definetly close enough.(Some have driven to T3 from Michigan for a the $1200 guide job).

Also rember the new guides are much improved parts which will last the life of the car and the new cam chain tensioners oil pump chain and oil pump chain tensioners that are part of this job are a good thing to have regardless.

Fred...:thumbup

PS: transmission prices are less than mentionend above.dealer 3.5k installed factory reman (even tho if u dont have a transmission cooler you should also get a new radiator at that time to protect transmission some dealers insist on that)Or you can get a factory reman for $1750 (this club has a couple of Infinti parts depts that give us substantial discounts) plus shipping to your installer.Installation depending on location varies between $500 to $700.

[gloucester Q]

jl-i asked the service manager at my dealer (a pretty knowlegeable q fan i might add) the same question. he's seen several failures come through his shop and he said more than anything he'd chalk it up to frequency of oil changes. i've never seen the chain guides, but my impression is that there is a small orifice through which oil passes, and it's small enough that it can get clogged rather easily--something that becomes more likely the longer you leave it between oil changes--he recommended 3k, nothing longer. among the other changes made to the guides after 93, this hole was enlarged and this problem solved. if i'm talking out the ying yang, somebody let me know, it's based on my memory of a conversation a while back. i'm with the others when it comes to changing them--decide what the car is worth to you and go from there. assuming you're in the clear as far as owning this car, a nominal investment from here will leave you with a car that's still got a lot of life left--150k miles or so? plunking down for a used '02 or '03 will leave you $30-40k lighter, which is pretty significant, and though i've never driven one, i would be hard pressed to imagine that it's better (all around) than the original q. i bought the 99 q45t thinking that it would be an improvement on every aspect of my original 92, and i couldn't have been more wrong. i'm now back to a low mileage 93, fully aware of the cost it'll take to maintain it, and happy to do it.

[PalmerWMD]

If you have a Q that is in good shape. $1200-$1300 is chump change.driving a car an worrying about that is no fun.

Get you service advisor on this site please.We need more dealer reps (even tho we will disagree on this issue)

Fred...

[DAEDALUS]

The oil ports are in the chain tensioners and I can see how they could get clogged up given enough dirty oil, but I don't think that would hasten the failure of the guide that fails most often. I strongly believe its failure is due primarily to the weight of the chain itself. The slack-sided guides (the ones on tensioners) were metal-backed originally.

[landtodd]

i've never seen the chain guides, but my impression is that there is a small orifice through which oil passes, and it's small enough that it can get clogged rather easily--something that becomes more likely the longer you leave it between oil changes

Your service guy was undoubtedly talking about the hydraulic tensioners (one each side), which are part of the chain/guide/tensioner team. In the end, the conclusion is sound -- not changing the oil often kills the motor.

Dennis has suggested a 3000-mile or 90-day change cycle, which makes some sense. Oil is incredibly cheap compared to that jewel of a motor.

[Q451990]

Well, here's my answer to the put-up-or-shut-up question..."what did you do?"

I've been sitting on "Q2" for over a year now driving it a grand total of about 65 miles since I got her back to Columbia 13+ months ago. Once everything else is ready to go she's going straight to T3 for new guides. If you want to wait that long, I'll tell you how mine look when they come out - but every engine is different! Mine spent all of it's life in the mild climate of San Francisco, so the warm-up cycles weren't nearly as harsh as NY!

I'd have them replaced if you're keeping the car. Otherwise you should sell it to me

Heath

[Q45ver]

You guys make me paranoid. My 91 Q has approx 30k on it now. I am taking chances I know, but at this stage I can't decide which is worse, let someone do it that I can afford who has never done the job or do it myself. (I'm an aircraft mechanic) Qtech has made it clear that this is not for the uninitiated and for me that includes local shops unfamiliar with the job. I maintain this engine religiously and will keep looking for a trust worthy shop to do it. If anyone knows of a guide experienced mechanic/shop in the north west let me know.

[DAEDALUS]

Welcome! 30k that is truly amazing. My advice is to do the guides yourself--it's less complex than an aircraft! Others have done them successfully with far less mechanical experience, and I have a hard time trusting a shop that has never done the job. In the end, you will care more about the labor done and less about how much time it took to do the job than the shop would. I made an outline of the job once:http://www.nissaninfiniticlub....=1632

[maxnix]

Q45ver, are you GlennSea from the old board?

I remember we had a couple of guys from Vancouver, BC, one of which found a real low Km. Q45. It was a beauty.

[landtodd]

Q45ver --

Ah, Vancouver. Beautiful area. Ah, a gen-1 Q with 30K. Hmmm . . . I'm jealous.

This was the car that was a Japanese exec's, and it just sat waiting for him in LA, right?

So, you're not driving it until you get the guides done? I understand and appreciate your caution with such a rare example. I hope no one starts talking about "over-investing" in this one! But then again, you bought it for a driver, right? Me, if I let my car sit more than a couple of days, the HLAs give up an annoying clatter on startup. Of course, for my car, 30K is a dim memory. Time to step up the oil-change schedule. Long and short of it, Qs like to be driven, and they seem happiest when they're driven a lot.

My feeling about the guides -- if your guy hasn't done this specific job before, you'll do just as well as he will. It's a great learning experience, probably a piece of cake for someone of your apparent talent, lots more fun than the under-plenum hose replacement. As you know, the only "special" tool you need is something that will remove/replace the 30mm crank pulley with 275 ft-lb. I cheated with my wonderful, magical impact gun, but more cautious heads really ought to prevail.

I don't recall whether or not you shopped the guide job with your first Q. My experience suggests you may have trouble finding someone to do the guides while leaving the chains in-place and un-replaced. Since guide-replacement isn't in their flat-rate book, everywhere I went, they found the closest job (the one they thought would get them close to the guides), which is replacing the chains. Then, four out of five said the guides couldn't be replaced without replacing the chains, which is (pick one or more) disinformation, ignorance, or salesmanship. Can't blame 'em. They just don't know . . .

As I recall, doing the guides without replacing the chains is a T3 innovation, the details of which Dennis graciously shared with us. All hail T3. And many thanks to Dennis.

[Q45ver]

No Maxnix, Glenn is a friend of mine. I was on the old board as Speckofsand, but due some log-in problems I have not been able to post for along time and decided to re-register. I am the lucky stiff that found the ultra low mileage Q. This thing is only now starting to show the odd wrinkle in the leather from being sat in. I just came back from a trip to LA and saw alot of these cars there, but here they are a real sleeper. I finally found a TCU from a 93 last week and it's on the way. I bought this car because of the memory of a test drive back in the early 90's. When I saw the miles (km's here) I had to check it out, it was even better than I had anticipated and couldn't open my wallet fast enough. This forum has since been an invaluable source of information. Thanks to all of you.

[Q45ver]

Sorry Landtodd, I posted from page one and didn't see your post. The source of this car was infact a Hong Kong exec commuting between Vancouver and Hong Kong. I have the maintenance history and most years he accumulated only a couple of thousand kilometers between visits back to the dealer for service. It was of course garage kept. He must have been single because the seats looked new. I am still running the original tires, although I may replace them by end of summer. Yes, I'm sure I could do the guide job myself, but Dennis warned of possible chain jump and made me a bit weary I guess. How far is T3 again? lol. I did the timming belt on my 87 maxima which may compare I don't know.

[maxnix]

Oh yeah, and don't you have a transmission cooler? Does Glenn have the Z wheels?

Good to see you again. If you work on aircraft engines and are familiar with bolting into alloy, it should not be much of a problem. Ardvarkus, Landtodd, Daedalus, and others are quite experienced with guides and more.

[K1XV]

I had the chain guide job done at T3 in Atlanta, driving down from NJ. Approx. 13 hours drive time. My old guides, at approx 128K, showed a little wear but no signs of catastrophic failure. Of course, I always changed the oil at 3K intervals. I am glad I had the job done for peace of mind. I would rather have T3 do it than someone else because the price was fair, and I would prefer that someone do it who has done it many times before rather than a first timer.

Also had other work done on this trip to Atlanta, and on the way home, the car drove the best it has in recent memory.

[landtodd]

The old guides often look okay when they're replaced, but there's something else to consider before calling them healthy -- brittleness. If we could find a set of plastic NOS guides that were never installed, we could compare the force it takes to snap them with our used, heat-cycled, yet in-tact guides.

My guess would be that used guides will be significantly more brittle. I saved mine in case I ever get such an opportunity.

[DAEDALUS]

I'll back up that comment. When DougQ45 did his guides, he quickly found that the best way to remove the old guide was to strike it once with a hammer. Those things shattered like candy glass.