VQ25DD Timing Chain/Engine replacement

[Spoddy]

Hi All,

I have a Skyline V35 with VQ25DD engine (215000km) that has engine noise.  The internet says its probably the timing chain, and it sounds like it to me. Runs OK otherwise. Is it possible to verify this is the cause before spending too much time/money on it? Am thinking perhaps I remove the small covers on each side of the timing chain cover (over the camshaft sprockets) and look inside. Not sure what to measure once I'm there however.

Assuming it is the timing chain I see a couple of options:

1. Fix the chain. Does anyone have any recommended kit brands and/or suppliers?

2. Replace the engine. Not many good ones around however. Is it possible to fit any other engines eg VQ25DE or perhaps a 3.0 or even 3.5L variant? Not too interested in spending a lot of time reprogramming ECUs. 

David

[joshuaho96]

25 minutes ago, Spoddy said:

Hi All,

I have a Skyline V35 with VQ25DD engine (215000km) that has engine noise.  The internet says its probably the timing chain, and it sounds like it to me. Runs OK otherwise. Is it possible to verify this is the cause before spending too much time/money on it? Am thinking perhaps I remove the small covers on each side of the timing chain cover (over the camshaft sprockets) and look inside. Not sure what to measure once I'm there however.

Assuming it is the timing chain I see a couple of options:

1. Fix the chain. Does anyone have any recommended kit brands and/or suppliers?

2. Replace the engine. Not many good ones around however. Is it possible to fit any other engines eg VQ25DE or perhaps a 3.0 or even 3.5L variant? Not too interested in spending a lot of time reprogramming ECUs. 

David

Use some rubber hose to narrow down where the noise is coming from. I couldn't tell you for sure whether there are any easy direct swaps but most likely you're going to need a new ECU at the very least.

[GTSBoy]

You're not swapping a 25DD with any other engine without it being a big exercise.

A proper timing chain inspection requires the front covers to come off so you can see the state of the tensioners and guides (which might be worn) and assess the amount of chain stretch.

[V35_Paul]

See if the noise goes away when you turn the AC off.

My mate was sure it was the timing chain on her 350Z but one day she turned her AC off and the noise was gone. Only make that awful noise when the AC was on. 

I assume clutch plate on the AC was the problem. 

Not the timing chain. So she sold the car in winter. Rude as.

 

[Spoddy]

I spent a bit of time trying to find the source of the noise, with and without a piece of garden hose. I dont think its the timing chain, I think its coming from underneath the intake plenum on the passenger side. Am guessing its an incorrect valve clearance. I'll take the intake plenum and rocker cover off tomorrow and poke around with feeler gauges.

I see it uses shims. Are these hard to get? Where do you get them from - is amayama.com OK or is there somewhere better? I guess I'll also replace the spark plugs and I'll probably need some gaskets.

 

Edited February 25, 2023 by Spoddy
poor terminology

[GTSBoy]

http://www.precisionshims.com.au/products/flat