Doing guides -- Chains too?

[bmwkiller]

I went to the local dealer to order chain guides. The parts guy told me I really should replace the chains too. He said the guides go bad, the chain slaps around, and it can stretch just enough to weaken it. I've seen posts indicating that it's not necessary to change them, however I've also seen posts that recommend changing the oil pump chain. Why one and not the others?Thanks

[elwesso]

The chains if I recall are pretty expensive... Also, in order to change the chains you have to rip apart more than just to get to the guides...... The lower front cover is all that needs to come off to simply change the guides... The upper front covres and valve covers (lots of extra labor) have to come off...

All in all, the VH45 chains are specially designed for anti-stretch... Theres a magazine article about it on Q45.org, how they double linked the chains or something goofy like that.....

Regardless, its a lot of extra labor for really IMO no purpose... The stock chains are gonna be good for a long time.....

THe oil pump chain ususally is changed because it does not have the same characteristics as the timing chains, plus its just a little itty bitty chain thats easy to replace......

[squeefoo]

I went to the local dealer to order chain guides. The parts guy told me I really should replace the chains too. He said the guides go bad, the chain slaps around, and it can stretch just enough to weaken it. I've seen posts indicating that it's not necessary to change them, however I've also seen posts that recommend changing the oil pump chain. Why one and not the others?Thanks

Wow! Um.. once the chains "slap around" from broken guides the motors toast!Stretch is not much to actually be worried about, (forget how much it is...) until about 300K + miles.

LOTS of extra labor to change the chain, it must be exact or (once again) the motors toast! I get a** pucker starting a Q after just guides and hearing the rattle... I can't imagine the pucker factor after chains.I think Heath said one tooth off and it runs like shyte, two and it's junk.You have to spin the motor around 6 times by hand to make sure they're right.

Forget it! ...the parts guy doesn't know what he's talking about , just do the guides... We'll help.

[3rd Q]

Yep, what they said. Q45tech has also mentioned in numerous posts that there is no need to do the timing chains as well.

I would only consider it after visually inspecting the chain while the front cover is off. There was one post a while back where the chain was stretched and cracked due to a piece of guide wedged between it and the front cover. So unless you've had something extreme happen to yours, don't worry about it.

Good luck and post if you need help!

Paul

[maxnix]

I've also seen posts that recommend changing the oil pump chain. Why one and not the others?

Timing chain don't usually stretch, but guide pieces readily fall into the oil pump chain path and cause mayhem.

[gniknave]

When it comes to the timing chain guides, ignore anything the dealer says. They're very misinformed when it comes to the older Q45 models as it is. Most have never done an engine rebuild on a Q45 to know exactly what happens when a chain guide breaks.

You have to figure, with all the newer vehicles in Infiniti's lineup - all of which use metal backed guides, the 90-93 Q45 if THE only one that used plastic. Most of Infiniti's service advisors, technicians, and parts counter people weren't with the company back then. Most people that own 90-93 Q45's don't take them to dealerships because of the cost of repair. You figure, if the uninformed owners of these cars drive them, yet can't really afford to maintain them, when the car dies they can't afford to fix it. It never see's the dealer.

Point being, it's a lot more cost effective for Infiniti to train it's employees on the current vehicles and most recent ones, rather than the older Q45's that don't come to the dealer much anyway. Can't blame Infiniti for that, but they shouldn't let their people give out misleading information either. Especially if it's not something they really know about.

In the mindset of an Infiniti service employee (or any other dealership) [Parts, Technician, Service Writer], you either replace all the parts while doing a certain job, or they won't warranty anything. For example, when replacing the transmission, the dealer will want to replace the radiator as well to make sure the transmission cooler cools the new transmission properly.

Same with the chain guides. One would think that if you're replacing the timing chain guides, then you'd replace the timing chain. The dealer will do it this way or just not warranty the work. In some cases, they might do it their way or no way at all.

Anyway, you have the proof of actual experiences of the people that own these cars and a few of us have actually done the chain guide job successfully on annumber of occasions. I think it's better to follow the advice of those who have done the job and experienced the results after the fact, than to listen to the dealer who's primary job is to sell as much as possible - since they're all commissioned.

The chains don't need to be changed, but do change the oil pump chain. It's easy to do and would only take you 5 minutes. If you need help with the job, post in Infiniti Online Mechanic (after searching first) and we'd be glad to help. If you're doing this yourself or having someone else do it, please make sure to read through the posts about chain guides on here so you know what - and what not to do. Search for posts by username: Tangalora

They will be most informative.

[gniknave]

Timing chain don't usually stretch, but guide pieces readily fall into the oil pump chain path and cause mayhem.

This is on 2 different cars. Oil pump chain shown in both.

[Q45tech]

It takes very little power to turn the cams because of light springs and light valves compared to turning the oil pump with cold thick oil.

[Flagship-Q]

In the mindset of an Infiniti service employee (or any other dealership) [Parts, Technician, Service Writer], you either replace all the parts while doing a certain job, or they won't warranty anything. For example, when replacing the transmission, the dealer will want to replace the radiator as well to make sure the transmission cooler cools the new transmission properly.

Same with the chain guides. One would think that if you're replacing the timing chain guides, then you'd replace the timing chain. The dealer will do it this way or just not warranty the work. In some cases, they might do it their way or no way at all.

Exactly, even with their covered warranty work. The previous owner of my Q had documentation of the transmission being replaced under warranty at 50K and they also replaced the radiator, fan shroud (newer, updated one apparenty), TCU, ECU, and installed external filter and cooler all in one shot.