Tapping noise during acceleration on 1998 Volvo S70 GLT

Volvoxlr8rs · Post by **Volvoxlr8rs** » 05 Mar 2007, 17:43

Hey after having saved several thousand dollars in repair and labor and lots of pain and grief by listening to the advise on this website I have finally become a member. I searched all over the site and did not see any links exactly matching this one so here I go. 1 Year ago I bought my 3rd and latest addition to my volvos after my wife crashed my red 95 850 turbo. It is an early 98 s70 glt which just clicked over to 104,000 miles. I bought it from it's origional owner with 80,000 miles on it. He had full service record with reputable dealer. After a few days I noticed a strange intermitten tapping noise. I know what fuel injectors sound like and this is different. It taps weather it is hot or cold. I always put primium gas in it. It only taps when the car is in gear from between 1100 to 2500 rpm. If I put the car in N and rev it no matter what I do it will not tap. I notice it most when I am driving up a hill and give it just enough gas to go up and maintain my velocity. If i push down harder or let off the tapping stops. It also does it @ about 55mph but not @ 70mph. I know it sounds crazy but that is exactly what it does. I have a mechanical background so I think I know when something is not quite right. On the bright side over the past 20,000 miles the tapping has only gotten slightly worse.

Any suggestions would be greatly appriciated. Thanks

Post by **Ozark Lee** » 05 Mar 2007, 20:33

An odd problem for sure. Does it sound like tappets/lifters? What weight oil are you running?

I've hear a lot of grousing about lifter noise when folks run 5W30 oil. I run 10W30 on mine so I have not experienced it myself.

That said, I wonder if there is a CV joint problem brewing since it doesn't do it in neutral in the same RPM range?

Do you feel any vibrations along with it?

...Lee

Volvoxlr8rs · Post by **Volvoxlr8rs** » 06 Mar 2007, 08:23

Thanks for replying Ozark. I always use Mobil 1 10W30 full synthetic. It does sound like a lifter to me but with the way it only does it only under certain conditions makes me question weather it could be one. I don't think it is the CV because it seems to be related to engine speed and not actual speed of the car. Example. Pulling uphill in second gear, going about 30mph. Engine @2000rpm the tapping is the same as it is in 4th gear @55mph @2000rpm. I talked to a mechanic who is not to knowledgable about Volvo's and he said that it sounded to him like something in the bottom half of the motor. Perhaps Rod bearings or something

! Lets hope he's wrong. I can't imagine that a bulletproof 5 cylinder which has been cared for pretty well cared fow would have something like that go wrong.

Volvoxlr8rs · Post by **Volvoxlr8rs** » 06 Mar 2007, 08:52

P.S. No Notable Vibration during tapping

jeovaz · Post by **jeovaz** » 23 May 2007, 18:17

Volvoxlr8rs wrote:Thanks for replying Ozark. I always use Mobil 1 10W30 full synthetic. It does sound like a lifter to me but with the way it only does it only under certain conditions makes me question weather it could be one. I don't think it is the CV because it seems to be related to engine speed and not actual speed of the car. Example. Pulling uphill in second gear, going about 30mph. Engine @2000rpm the tapping is the same as it is in 4th gear @55mph @2000rpm. I talked to a mechanic who is not to knowledgable about Volvo's and he said that it sounded to him like something in the bottom half of the motor. Perhaps Rod bearings or something ! Lets hope he's wrong. I can't imagine that a bulletproof 5 cylinder which has been cared for pretty well cared fow would have something like that go wrong.

I have an 850 T5 and yes, I get the same tapping sound? Did you find out what's causing it?

turbotim2 · Post by **turbotim2** » 24 May 2007, 08:08

Sometimes you can get this with a small exhaust leak. Can sound similar to lifters.

turbotim2 · Post by **turbotim2** » 24 May 2007, 08:09

Usually at the manifold...

Post by **pfeener** » 24 May 2007, 08:41

I agree. It definetly sounds like an exhaust leak. A small exhaust leak will behave exactly as you describe your problem.

Valve lifter noise should be there all the time and a lower end bearing or piston noise has a much more metalic sound than a lifter and it usually reduces in intensity under load.

Post by **akitawagon** » 27 May 2007, 00:29

I'm not sure if my issue is the same as yours, but I had a fairly loud tapping/fluttering/ratcheting noise (almost sounded like a mechanical problem) that occurred when giving gas for accelerating or climbing hills.

I thought it might have been an exhaust leak, but turned out to be that one of the elbows attached to the vacuum tree by the IAC valve had cracked at a bend that wasn't visible until I removed the vacuum tree for cleaning out the throttle. Fixing the bad elbow seems to have eliminated the tapping/fluttering noise and my car feels like it's gained some of its low end torque back.

Post by **pfeener** » 27 May 2007, 07:28

Just so you know exactly what's happing; when the "O" rings for the oil pan shrink up a little, it can allow a small amount of air to get sucked into the oil stream and pumped into the oil system. It won't do any harm to the mechanical parts of the engine (bearings, cams, etc) , but the air in the oil will get into the hydraulic lifters and won't allow the lifters to be pumped up solid. Hence the tappet noise.

Here's the original link for the "O" ring replacement. I think it has a little more info.

http://volvospeed.com/vs_forum/index.ph ... =11441&hl=

You might want to do a search on volvospeed.com as well. I think that's where the original post came from and I think you may be able to find some pics as well.