'91Q Chain tensioners

[timatt]

'91Q; almost 150k miles.

When I start my engine I often get a rattley sound for 1-2 seconds, kinda freaks me out, but goes away and the engine runs smooth and quiet. To me it sounds like the timing chains rattling until the chain tensioners pump up, but I'm not certain that thats what it is. I've tried different oil filters thinking it might be the backflow prevention valve, but no success.

BTW the chain guides were replaced at 80K miles (originals were intact when removed).

Is this a common issue with the VH45DE?

Should I be concerned?

Tim

[Q45tech]

Get some BG Quick Clean for Engines and follow the directions precisely!

Start out with fresh oil and filter for best results add BG idle [at least under 2,000 rpm] for the period then drain and install brand new oil and filter.

When the chain guides were replaced did they also change the tensioners at the same time.................always a good idea to change them every 100k even with new guides.

I periodically use the Quick Clean every 2 years [30k] just to clean up varnish.

[timatt]

Thanks for the quick response. I will try the BG clean at next oil change. I've already tried the ATF approach just before the last oil change and that didn't seem to help.

Tensioners were not replaced with the guides; probably should have been.

Am I risking engine failure here?

Tim

[maxnix]

Tensioners were not replaced with the guides; probably should have been.

Am I risking engine failure here?

You could be. Weren't they examined carefully when disassembled?

[timatt]

More info:

I talked to my mechanic that did the chain guides 3 years back. He feels fairly sure that we replaced the tensioners at that time. He says he would have squawked if we didn't.

Also spoke to the kind folks at T3 about scheduling the car in to have the tensioners replaced (among other things). He said that he felt that new tensioners would not necessarily fix the problem and talked me out of replacing them. He stated that it's not uncommon and is a result of normal wear. He also indicated that his own high mileage Q does the same thing and has for quite some time, and that it's highly unlikely that the chain will slip causing mistiming of the cam and engine damage.

Still haven't done the BG engine flush yet but plan to soon

Tim

[maxnix]

Thanks for the update. I wonder if you are just hearing the HLA being repressurized? Long intervals between start-ups? Sounds like a bunch of small marbles in a can.

Q45tech's recommendation is specifically for removing varnish that may prevent oil retention. After a few days, HLA will all bleed down.

Try this. Remove Fuel pump fuse and turn engine over for at least 30 seconds before intitial start-up. Replace fuse and start. If noise is less, HLA are indicated.
Modified by maxnix at 8:05 AM 10/3/2006

[Q45tech]

You got the not sure answer about tensioners because T3 doesn't want to change you $1000 and not have the problem fixed.

Also we assume [often incorrectly] that a chain guide job was done correctly..........we see the slack side guide only changes, or the skipping of oil chain, or oil guides, or other short cuts................which may or may not reduce reliability..............noise sources.

A 150k or a 300k engine [which has had 16 years x 4 =64 oil changes] should be quite as a mouse............unfortunately people skip/extend the 90 day oil changes when they drive few miles per year.

[timatt]

Q45 TechOK: I'll try to answer each issue you've raised.

I am aware of what T3 charges for the guide job and do not have a problem with the expenditure. If T3 were closer, I would have had them do the job. Since they are not, I had my mechanic do the guides. All four guides were replaced; I know since I got the old guides back from the mechanic (and posted pics of them here). The oil chain was replaced since it was cheap as were the guides. I've known the mechanic who did the work for many years and know that he is competent, not a hack, not the type to cut corners.

I purchased the car at 60k miles and it appeared to be well maintained all the way around (right Wes?). I put a minimum of 30k miles on the car annually so I never get past 90 days between oil changes (Mobil 1 every 10k, new filter every 5k). When I re-sealed the valve covers 2 years back, the inside was clean, no sludge anywhere.

So what should I do here? I want the thing fixed right. I've got the car scheduled in at T3 for new motor mounts, O2 sensors and some other work during the second week of November, since I'm passing through that Atlanta. It will be there 3 (week days).

Also, I'm not up on my acronyms; What is HLA?? As Manix suggested, it does sound like marbles in a can on startup.

Thanks for the help.

[Q45tech]

HLA are the oil pressurized roller cam follower adjuster............a modern version of the old valve lifter which used push rods unit.

To my knowledge T3 has never changed out HLA as it is less expensive to replace the engine.

Normally takes 2 weeks plus for them to bleed down unless excessively worn.

Let Byron [T3 South Cobb] decide what to do after he hears the sound in person.

[maxnix]

HLA = Hydraulic Lash Adjuster

Spend some time with the FSM and TSB and it will help you immensely when dealing with service providers.

FSM = Factory Service Manual

TSB = Technical Service Bulletin

We need a glossary.

[elwesso]

Tim, when i saw your Q it definitely does sound like a tensioner... You can always try and replace just the drivers side tensioner as it can go in/out in about 5 mins... maybe youd get lucky... The passenger side tensioner, I THINK, does not require removal of the front cover, you jsut remove that little access panel....

When i helped ross with his guides, i left one of the tensioners loose and started it up and it sounded just like your noise.... HLA noise is more of a rhythmic TIC as you know....

[Q451990]

HLA = Hydraulic Lash Adjuster

FSM = Factory Service Manual

TSB = Technical Service Bulletin

We need a glossary.

Amen to that! Maybe we could create one and make it a sticky? Include (dare I start this again) the car factory names, abreviations, etc...

Heath

[elwesso]

Amen to that! Maybe we could create one and make it a sticky? Include (dare I start this again) the car factory names, abreviations, etc...

Heath

something like this woudl probably better serve as an article.... IF someone wants to get started on one, i can start it and we can add as we want.

[Q451990]

something like this woudl probably better serve as an article.... IF someone wants to get started on one, i can start it and we can add as we want.

Here's my attempt... is there a way that we can open it so that all members can update one post vs. quoting and adding to the end of it?

zer...id=24

Heath

[elwesso]

best thing for people to do is to just reply and then I can add it to the various places....

Ill post this up in other forums to get this moving.

EDIT: Just so you know heath, im gonna preface the thread with "rules" since I intend that all of NICO contributes to this, not just the Infiniti guys.

[Overcamber]

Tim, when i saw your Q it definitely does sound like a tensioner... You can always try and replace just the drivers side tensioner as it can go in/out in about 5 mins... maybe youd get lucky... The passenger side tensioner, I THINK, does not require removal of the front cover, you jsut remove that little access panel....

When i helped ross with his guides, i left one of the tensioners loose and started it up and it sounded just like your noise.... HLA noise is more of a rhythmic TIC as you know....

is there a maechanical adjustment for these tensioners or are they spring loaded...It sounds like I've isolated my noise to the passenger side tensioner amd was curious what I'd find pulling that little cover off?..thanks in advance mine is a 94 Q45

[Raxephon]

There is a spring inside the plunger for tension prior to oil priming the plunger chamber .

My old spring was worn, not so resistant to recession of the plunger.

I just slapped a higher tension spring in mine and haven't had any problems out of it yet.

Now, depending on the tension of the new spring, you should expect some additional wear if the spring rate is too high.

Mine had a "Tack tack tack tack" noise at start-up until I added the spring. I originally thought it was a valve, but with no loss of compression I was skeptical, so I took a mechanics stethoscope and went searching.

[Overcamber]

thanks for the reply..I'll be doing more searching on Saturday when I see the car again..

[Q45denver]

I wonder why T3 is charging $1000 for these if it only takes a few minutes to replace them?

[cientortas]

I wonder why T3 is charging $1000 for these if it only takes a few minutes to replace them?

I'm curious as well.

Can both tensioners be removed and replaced without removing the front cover? Is there any risk of the chain jumping teeth when the tensioners are removed?

Maybe T3 needs to remove front cover, secure chain, and then replace tensioners to avoid "chain jumping."

[Q451990]

I bet the $1000 mentioned was for the entire guide job.

Heath

[Q45tech]

Due to risk, T3 won't replace JUST chain tensioners without removing front cover to lock down chains with tiewraps.I guess you could sign a written waiver document and assume all risk and cost if something went wrong. Just as customers assume the potential extra cost on a $1000 chain guide job to pay an additional $510 to remove oil pain to fish out broken guide pieces and clean pickup if guides have failed and broken apart.

Just as the potential for recommending a $500 oil pump replacement ocassionally occurs when a chain has eated 90% of shaft thru and will probably fail soon.

You never know what you find when you open up front cover.

As a business, you cannot afford to do work which might have a 50% chance of costing you money because of a subsequent ever since complaint.

It has been 11 years [May 97] and 218,000 miles since my tensioners were replaced along with guides.