Maybe a Timing Issue?

[elemgee]

When my 92 SVX is warmed up, I hear a knocking coming from the engine at idle, and its fairly noticeable from inside the car (I dont really hear it when I'm hovering over the engine). Its like 2 knocks per second or so. And, when accelerating fairly quickly, the engine shakes. Nothing violent but noticeable. This started happening fairly recently. The car only has 42K miles on it. Any ideas what it could be - I was thinking, maybe the timing is off (this is my 3rd SVX and the mileage is significantly less than my previous 2, which I thought could also be timing related)? And related to this, how do I check the timing? Did a search and didnt find anything.

Thanks.

Larry

[kwren]

Originally Posted by elemgee

When my 92 SVX is warmed up, I hear a knocking coming from the engine at idle, and its fairly noticeable from inside the car (I dont really hear it when I'm hovering over the engine). Its like 2 knocks per second or so. And, when accelerating fairly quickly, the engine shakes. Nothing violent but noticeable. This started happening fairly recently. The car only has 42K miles on it. Any ideas what it could be - I was thinking, maybe the timing is off (this is my 3rd SVX and the mileage is significantly less than my previous 2, which I thought could also be timing related)? And related to this, how do I check the timing? Did a search and didnt find anything.

Thanks.

Larry

Larry, as far as I know out of time would mean that the timing belt might be a problem. Might check out the alignment marks and check the cam shaft sprockets as well. Occasionally there has been rusting out in the sprocket-cam shaft-key area.

If the timing belt is original, probably time for a replacement considering the age of the car, even with that lo-mileage.

I had that problem and a Subaru dealer worked on it for 6 or 7 weeks, while I drove a new Subaru loaner, they couldn't work it out, so they gave up, I brought it home, found the problem, and repaired it myself. (we pray a lot)
Hope this helps
Keith

[92snowmachine]

if you take off the two side covers for the timing belt you can turn the crank to align the mark on the balancer to 0 and check to see if the marks on the camshaft sprockets align with the marks on the rear of the cover. does it run ok? usually timing belt issues don't care if the engine is warm or not. an easy way to check if your timing is off is to put a vacuum gauge on a vacuum line and see if the readings are low (less than 15") or if the gauge is fluttering rapidly.

[elemgee]

OK. Just want to check - with the SVX you cant check the timing with a timing light, and theres no way to check the timing using a method similar to that for viewing "check engine" codes (you know,place that plug thing into the little black plastic connector, count the number of times something flashes, etc)?

And to answer the question above, the car seems to idle OK except for the knocking sound, but when accelerating, the engine shakes (not violently, but enough to be noticeable).

[elemgee]

Originally Posted by 92snowmachine

if you take off the two side covers for the timing belt you can turn the crank to align the mark on the balancer to 0 and check to see if the marks on the camshaft sprockets align with the marks on the rear of the cover. does it run ok? usually timing belt issues don't care if the engine is warm or not. an easy way to check if your timing is off is to put a vacuum gauge on a vacuum line and see if the readings are low (less than 15") or if the gauge is fluttering rapidly.

One other question - if the above shows that the timing is off, can it just be adjusted fairly easily without replacing/removing the belt? And if so, how (OK, so thats 2 questions).

[SoCal LS-L]

Originally Posted by elemgee

One other question - if the above shows that the timing is off, can it just be adjusted fairly easily without replacing/removing the belt? And if so, how (OK, so thats 2 questions).

The belt has to be untensioned, so no on that question.

Its a simple check, you just TDC the engine with that big fat crankshaft bolt, then pull your side covers to make sure they are in time with the crank pulley notch. The pass. side one is more of a PITA but removing that fat canister and the bracket makes it easier to get off.

The ignition timing is controlled by the ECU directly, which uses the inputs from the sensors on the cams. Thats why you have to make sure you are still in time.

If its not this it sounds like you have some kind of miss. 46K means engine sat A LOT and probably wasnt mothballed. Machines dont like to sit with fluids in them for long periods of time unused.

[92snowmachine]

unfortunately you can't check the timing with a timing light because the ignition timing is computer controlled, and the data from the computer isn't really helpful unless you have a serious problem. if you take off the covers and the timing is off then you can adjust it by loosening the tensioner bolts, removing an idler pulley and having a helper turn the cam sprocket a notch with an open ended wrench while you slip the belt into the next notch (they are usually only out a notch or two). although if it has slipped you might want to go ahead and replace the belt and make sure all of your pulleys and the tensioner are ok.
can you hear the noise well from underneath the engine or transmission area? is sounds like one of your cylinders might not be firing all the time, try pulling off injector connectors one at a time and make sure that the rpms drop the same amount for each cylinder.

[SoCal LS-L]

Originally Posted by 92snowmachine

unfortunately you can't check the timing with a timing light because the ignition timing is computer controlled, and the data from the computer isn't really helpful unless you have a serious problem. if you take off the covers and the timing is off then you can adjust it by loosening the tensioner bolts, removing an idler pulley and having a helper turn the cam sprocket a notch with an open ended wrench while you slip the belt into the next notch (they are usually only out a notch or two). although if it has slipped you might want to go ahead and replace the belt and make sure all of your pulleys and the tensioner are ok.
can you hear the noise well from underneath the engine or transmission area? is sounds like one of your cylinders might not be firing all the time, try pulling off injector connectors one at a time and make sure that the rpms drop the same amount for each cylinder.

If you do this expect to remove some parts to take your tensioner out and recompress it. Basically a full timing belt job, since the middle cover has to be yanked to get to the tensioner and the belt would be loose ready to come out. Just letting ya know, check it first and then tell us what you find, we will go from there.

BTW 92Snowmachine, go Avalanche!!! Im gonna be moving back there in about a year, been an Avs fan since we stole them from Quebec.

[92snowmachine]

go AVs. Never was a fan of hockey until we got a team and they kicked butt. I agree if the timing is off then he should probably do the belt but myself just slid the tensioner to the side enough to get some slack for the belt to move, not adviseable but friday afternoon mechanics have to do some hillbilly stuff.

[kwren]

Again...

Originally Posted by kwren

Larry, as far as I know out of time would mean that the timing belt might be a problem. Might check out the alignment marks and check the cam shaft sprockets as well. Occasionally there has been rusting out in the sprocket-cam shaft-key area.

If the timing belt is original, probably time for a replacement considering the age of the car, even with that lo-mileage.
Keith

Hope this helps
Keith

[SoCal LS-L]

Originally Posted by 92snowmachine

go AVs. Never was a fan of hockey until we got a team and they kicked butt. I agree if the timing is off then he should probably do the belt but myself just slid the tensioner to the side enough to get some slack for the belt to move, not adviseable but friday afternoon mechanics have to do some hillbilly stuff.

Were tops in the NW, 3rd in the west, and have a league leading 118 goals. Wait till Stewart and Stastny get back, and maybe even Mueller someday. How bout the new guy we offloaded Hannan for? Only Av since Sakic to score a hat trick in a single period.