Guys,

I replaced the spark plugs recently and lifted up the engine, by removing 2 engine mount nuts (14mm) and lifting with a car jack.
I tightened those 2 nuts back when the car's front end was on the ramps and the engine was off. After that procedure I started noticing a single clunk nouse\thud (from the front end, right side - feel in my legs, JDM car) at the first second if I take off, start moving aggressively.
If I start slowly, there will be no thud. It comes only when I start sharp.

Check and tighter the suspension components - no change.

I am wondering was it ok that I tightened engine mount nuts when the front end was lifted? The car was not horizontal.
Should I tighten the nuts while the engine idling? Seemed like tightened nuts have the same locations as before.
Should I release the upper mount nuts as well?

Please advise how I should re-tighten the engine mounts. THANK YOU Guys.

 

Ideally cheack the upper mount as it may have slipped slightly. it could be worth loosening all three mounts, just incase youve introduced tension to one if that makes sense, and tighten them again.

You really dont need to lift the engine to do spark plugs though. Done mine multiple times without doing so. The best thing to do is spend a little time experimenting with different length sockets and adaptors, theres even a subaru specific socket out there for spark plugs. Ive never needed it as i have a combination of sockets that work

 

He was told

 

From the sounds of it he needed it. lol

 

Going to make all the mounts loosen and re-tightened this weekend. Maybe the upper one needs to be tightened.
I know some people are able to replace the plugs by not lighting the engine, but as I know, Impreza has more space under the hood, but Forester SG5 has more space limitations.
I tried not to lift the engine and I have a number of extending adapters, but anyway it was not easy to get the spark plugs out. Once I lifted the engine, the process turned out to be so easy.

 

Never worked on a forester so you will certainly know better

I hope its just the top pitch mount loose, im thinking that when you lifted the engine you probably should have disconnected it anyway.

Id have a look under the top mount IC and make sure its still in 1 piece worst case it snapped and you have to replace it.

Im just struggling to imagine what is moviig so much you can feel when driving!

 

When you lifted the engine you should have disconnect the pitch stop mount too. If this was left connected, when you lowered the engine back into place it could have torqued enough that it’s hung up on a thread. Admittedly it should’ve found itself home, but it’s possible. Just undo the pitch stop mount, and then the two lower engine mounts, jack the engine back up slightly and then lower is again and make sure it’s home properly. Then do up the engine mount nuts and re-fit the pitch stop.

 

To be honest, I watched a few videos on youtube of the guys replacing the spark plugs on SG5 by lifting up the engine, and nobody touched the pitch stop mount, they just loosened two lower mounts only - so I did.
That single clunking noise\thus can be heard only when I take off sharp, not normally or slowly accelerating. Otherwise, there are no other noises or vibrations. I don't think that pitch stop mount is broken, maybe it slipped and loosen, I believe.
I will try to re-tighten all the mounts tomorrow. Will keep you guys updated...

 

the pitch stop has to be loosened otherwise your fighting against it when you raise the engine..........

have worked on all forms of Subaru for circa 25years and never lifted an engine for plugs

 

It's almost like not everybody uploading to Youtube is an expert

 

Being fair, a 5 minute search on here, or even a question would have told you how to do it without this extra issue you now have,
These cars have been around decades so there is certainly a lot of information at your finger tips these days.

 

 

Update:
1 Loosened the pitch stop mount, and the two lower mounts. The Pitch stop mount looked absolutely fine.
2. Started the engine for a second (the intercooler was removed so the engine stalled, but worked for a few seconds).
3. Tightened the right lower mount, then the left lower, and finally - the pitch stop mount.
Result: no more thud\clunking noise.

 

Good news

Did you notice if it had moved at all? One of the bolt holes is sloted for adjustment.

 

I did not notice anything. Here are some pictures. Basically, I just removed the pitch stop mount and installed it back.

 

The elongated hole is on the bulkhead.