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Hello Hello
I have a 98, v90 with 160k miles and it is the 2.9l engine.
The car is newer to me and I am trying to figure out a couple of issues.
I've noticed when I start the car in the morning, after about 30 seconds I get a pretty loud knock/tock. It goes for about 2-3 minutes with a consistent beat. Maybe 1 knock every 1/2 second. Then it seems when the car reaches a certain temp it goes away. Trying to figure out exactly where it is coming from, I put a small hose to my ear and it is loudest behind the upper timing belt cover where the cam sprocket meets the engine.
Any ideas or thoughts would be greatly appreciated.
Also, I pulled the front of the timing belt cover off to take a look. I didn't see anything unusual but I did notice, the top of the rear tb cover, seems to rub on the belt, in two spots near the corners. It almost looks like it is a guide, integrated into the cover, but I can't imagine rubbing on anything is good?
Kindly
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Hey everyone,
Thanks for all of the thoughts.
Quick update. Looking at receipts from the previous owner, the car had an oil change 1000 miles ago, using "high mileage" oil which I have read I'd a no no for the white blocks.
I changed that out yesterday to full synthetic 5-40.
When I started it up this morning I could still here the knock but it was way quieter than before. Maybe a coincidence but I'm guessing the oil had something to do with it.
I have it going to a shop next week to look at vibration problem I'm having. Per one of your suggestions, I'll have em check the oil pressure while it's there.
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Curious: Still getting any knock after start up? Or did it disappear?
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Will I buy another Volvo??? We'll see....
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Hi
Thanks for the follow up.
Yeah unfortunately I'm still getting it but it's not as loud and I haven't noticed everyday, which has me more confused. It went two or three days I didn't notice it but came back today.
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I'm thinking just the fact you gave it fresh new high quality oil with quality cleaning additives is starting to help loosen a sticky exhaust valve or lubricate a worn stem seal. High mileage oil mostly just has seal conditioners as an additive, otherwise they have the same lubrication properties and SAE ratings. Any additional wear additives are mostly just advertising IMO or else they'd be in all their oil. High mileage oil is generally not recommended for engines in good shape seal-wise. The seal conditioners cause the crank, cam and any intermediate shaft oil seals to slightly soften and pucker. For a worn seal that's fine, it helps keep oil from weeping past the seal and defers the need to replace it. For new seals they cause premature seal wear, shortening their lifespan. For red blocks, the front seals are easy to replace, so a little premature wear is no big deal. The rear main seal is a different story, difficult to replace and often goes past its best before date and starts to weep, as seen under the bell housing. With my high mileage red blocks still on their original rear seals I do occasionally use high mileage oil when it's on sale. The tradeoff is I use the best front seals I can get and I've got no problem if they need to be replaced a year earlier. If the front seals in the white blocks are more difficult to replace then I would avoid high mileage oil.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
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Thanks for all of the thoughts.
According to a carfax I have on it, the tb, water pump and tensioner were replaced about 25k and 5 years ago.
I started it today without the tb cover on to inspect further.
I didn't notice anything in there that would cause this noise.
I was able to verify again the knock comes from behind the exhaust cam gear. It's really bizarre, I start the car and there is no noise, about 1-2 minutes later the knock/ cluck starts and last for about another 2 minutes then goes away. I also noticed it fades in, gets progressively louder then fades away.
I don't believe it is piston slap but that is only based on a piston slap noise I had on an 96 subaru which was not the same as this sound.
In the next week or so, I will give it a change to synthetic oil and see what happens.
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Hi,
If you haven't solved this yet, I suggest you give a look at your exhaust manifold gaskets.
I wouldn't have believed it until it happened to me, but a failed or failing gasket can make a knock that mimics a rod knock.
They don't usually doesn't come and go but strange things sometimes happen.
It could possibly be explained by the fact that the manifold gets hot and expands before the block does. And then maybe when the block eventually expands it seals it back enough not to be noticeable.
Good luck,
Peter
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Check timing belt tension. Timing belts can harmonically flutter on the long span after the crank pulley on the exhaust side, make noise and even touch the cover. Belt length affecting tension and belt flexibility will vary by temp, which would change the flutter. The DOHC B234F (for example) has a small stainless steel wear plate on the inside of the cover at the mid-span point for that reason. If you've got an automatic hydraulic tensioner then it may be slowly failing (I didn't check, but I'm guessing you do, especially if it's an interference engine). Inspect carefully at the base of the pulley arm to see if there's any hint oil residue indicating a leak. Other than measuring belt tension. there is no good test of hydraulic tensioners that have only started to go. They are considered a wear item and need occasional replacement.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
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Dave makes a good point about the tensioner and timing belt. Do you have a service record when they were last changed? If no record then check for a timing belt replaced sticker under the hood.
They are normally changed together on the white block engines. Just found the interval. According to 700/900 FAQ, it is every 70k miles similar to the 5 cylinder engines of that era.
I must say, however, that I am a little skeptical that a bad hydraulic tensioner or sloppy timing belt could cause a loud knock. Also, that it only makes noise when the engine is cold.
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Will I buy another Volvo??? We'll see....
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Does it sound like rod knock or more like a loud ticking sound? Good news is we know it’s not rod knock since it goes away when warm…:)
Ticking when cold could be a bad o-ring on the oil pickup tube. Hopefully not, as you have to drop the sump to to replace them. O-rings are cheap but not the labor unless you can do it yourself.
Maybe the oil passages are gunked up and the lifters aren’t getting enough oil when cold. Especially if conventional oil was used by the previous owner. You could try running a cleaner such Sea Foam, Marvel Mystery Oil or even less than half a quart of synthetic ATF in it for a short time to see if that helps. 500 miles or so. Then change filter and refill with synthetic as Bill suggested. BTW - Marvel Mystery oil worked on my 95 950 when I had lifter noise.
A no-cost option is to try a high engine speed tune up. Drive for awhile to make sure the engine is good and warm first. Then on a divided highway rev the engine to about 4000 rpm and HOLD it for at least 5 minutes. The heat might burn off any gunk buildup in upper end of the engine.
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Will I buy another Volvo??? We'll see....
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Thanks for the replies and thoughts.
It's definitely not a ticking sound. I do have those sounds too 😀 but I assumed those are normal as my 2015 xc70 also ticks.
This is definitely a knocking sound or like when you cluck your tongue. And again it seems to be right next to the exhaust cam sprocket.
The oil is not synthetic. It's a Castrol high mileage based on one of the receipts I found. I was planning on switching to synthetic next change. Maybe I should change in now?
I've read there was a tsb for crank bearing in these vehicles. Would that be by the exhaust cam?
I'm trying to upload a pic of the tb rubbing points bur am not having much luck
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Change to synthetic ASAP. Have your oil pressure checked! Low oil pressure can be caused by bad bearings. Low oil pressure will also make your lifters very loud because they are oil starved.
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Will I buy another Volvo??? We'll see....
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Hi,
What are you running for oil?
I'd steer clear of dyno oil for it's inferior performance,
including clogging up oil galleries in the cylinder head and the EGR system.
Use only Full Synthetic.
Bill
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Hi,
I hear that a lot. My 90 240 has 350 k on it and and runs like Swiss watch. At 5k oil change intervals there's no measurable oil loss, and it's never had a drop of synthetic oil. I must be doing something wrong.
Peter
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Hi Peter,
Synthetic is just better oil and more forgiving to those types that
don't change oil on time like you do.
The 940 Volvo user manual suggests Full Synthetic for severe service,
towing, etc.
Dyno oil is poison to white block engines.
What's your email, I'll send you photos of what dyno oil does to an 850.
In this post it seems like the oil isn't flowing until it warms up.
Synthetic flows better when cold, this was why I posted.
Who knows what the previous owner has in the crankcase, maybe he was retro and
added STP?
Check out Walmart for good prices for oil and see that their full synthetic
isn't much more than Castrol Hi Mileage Dyno oil.
Synthetic Oil vs. Conventional Oil
https://www.autozone.com/diy/motor-oil/synthetic-oil-vs-conventional-oil-which-is-better
Synthetic Oil vs. Conventional Oil
https://www.mobil.com/en/lubricants/for-personal-vehicles/auto-care/all-about-oil/learn-about-motor-oil/synthetic-oil-vs-conventional-oil
Bill
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