I just purchased a 2001 Grand Virtara XL7 that was known to have a bad water pump. Reading here on this forum I also learned that the #1 tensioner on the main timing chain is a common problem. So I thought while I had the front cover off it would be a good time to replace that. I ordered the tensioner before I got the cover off (this past Monday). Well Tuesday I finished up getting every thing apart... the main chain where the #1 tensioner is very tight. up on the middle of the motor where it looks like just a idler gear pulley is very loose... There is also a small chain on the bottom right (looking at the motor from the front) that is really loose.?.?.?. how do I tell the tolerances? I bought this car to fix and sell... but do not want to have my name attached to a ticking time bomb...
If I need to I can take a video and post it up here to show you what I am talking about....
I got busy and didn't address the loose portion of the timing chain earlier.
The looseness / tightness of the chain sections you ID'd will self correct when running. Two things are going on now that has them in a state that they are in while sitting still.
1. Is that fact that the hydraulic (engine oil pressure fed) tensioners aren't protruding / adjusting at the moment. That will give you chain slack.
2. Is the act of the camshafts themselves being off their lobes tops and with valve spring tension are trying to ramp down (or back) applying a "turning" effort to the sprockets. That all settles out when running.
'99 Grand Vitara JLX, 2.5L V-6, 4WD, 5 spd std, '00 "Limited" leather interior.
'03 Honda Odyssey
'72 Chevy Nova. One owner, SB, A/C, power disc/drum & steering.
I have a similar situation as Super10brss. I have a 99 GV that I purchased brand new (Melbourne, Australia). It has 143,000km, oil changed every 10,000km (except the last 2 I left for over 15,000kms). It started making the dreaded rattle in the engine that is explained everywhere on this forum.
We’ve pulled the timing chain cover off. Initial inspection last night:
1. The 3 timing chains appear tight.
2. But the oil pump drive chain is very loose.
3. The tensioner No.1 is intact and appears ok.
Questions for you:
Q1. Do you have any instructions on how to determine if the 3 timing chains are tight enough? Same for the oil pump chain. How tight should it be when they are not running.
The looseness / tightness of the chain sections you ID'd will self correct when running.
Q2. Are you suggesting that the oil pump drive chain may be loose because it’s not running?
Q3. Are there any signs to look out for to verify that the tensioner No. 1 is faulty?
My initial thoughts at this stage are:
1. Was it the oil pump chain that was loose and making the rattle? If so, do we just adjust that and leave all the other timing chains? I know that the new recommendation is to change all the timing chains, but that's a big job.
2. Do we change the no.1 tensioner now anyway since we are already there? Even though it looks ok and the chain tension looks ok, it may be faulty.
You can adjust the oil pump chain slack by repositioning the chain guide, if the chain or guide are not worn to an extreme. I can't say that this attributes to your noise, unless the slack is so extensive that the chain is slapping / contacting a surrounding part.
From the Service Manual, in part...
Volume 2 of 2 page 6A2-26 ENGINE MECHANICAL (H25 ENGINE)
2) Hand-tighten oil pump chain guide bolts.
3) To take up slack of oil pump chain, push center of oil pump chain
guide with a force of 0.5 to 0.6 N (50 – 60 g, 0.11 – 0.13 lb) then
tighten oil pump chain guide bolts to specified torque.
(e): 11 N.m (1.1 kg-m, 7.5 lb-ft)
On the valve timing chain slack...is the #1 tensioner ratcheted out / protruding significantly? That would indicate that chain or guide wear is significant as well. Also that and the tensioner has reached the max adjustment. Are the guides visibly worn / grooved? That too is signs of needed replacement.
I don't know of a way to qualify if the chains are worn / stretched other that maybe a comparison to new ones.
With a normal / serviceable amount of chain slack, the #1 tensioner plunger distance "stick-out" looks like...
IF all looks relatively proper, I'd replace the #1 tensioner, as the early (99'/2000' 2.5's) were prone to weakness that was corrected in subsequent years & new replacement units.
An update. My brother changed the tensioner no. 1. I've attached a photo so that others can see. The oil hole was definitely blocked with some sort of grit. So, we were quite confident that this would resolve the noise problem. We also got a mechanic friend to inspect the chains and he said no need to change the chains, just change the tensioner no.1. All else looked ok. The oil pump chain was tightened slightly.
Started it up. All sounded ok for about 2 minutes. Then the noise reappeared. No change.
a) I initially took it to Suzuki. The first mechanic said it's most likely the timing chain. The head mechanic made the final conclusion and said, no, it sounds like it's the torque convertor. It's not coming from the engine.
"Hoisted vehicle. Found noise from gearbox area. Possible torque convertor."
b) I took it to an auto transmission place. The guy initially said, it's definitely the torque convertor. Next day, he said he can't work it out. He said, it's definitely coming from the engine. It's not the transmission.
"Check vehicle for noise. Remove covers and check. Check flex plate. Noise coming from engine."
c) The transmission place recommended a mechanic around the corner. I left the car with him, and he said it's definitely the timing chains but he wanted to overhaul the entire engine for $4200 which I didn't want to spend.
d) My brother and I saw the forums online suggesting tensioner no. 1. We decided to have a go ourselves and change it.
When you listen, the rattle does seem like it's coming from under the car.
Any other clues? Engine runs fine. No loss in power, no engine shake, no smoke, tested all the piston pressure, all ok and within limits.
Is the fact that it only happens when it's warm any clue???? When you start it, it's quiet.
Any ideas would be appreciated. My only options now are to:
a) take it for another opinion with a different suzuki mechanic.
b) take it to another transmission place, maybe it is the transmission and the guy was wrong??
I'm lost and I don't want to give up on my car just yet if it's something simple.
If it helps, I can post a video with the engine running so you can hear it.
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