Bad cold start ticking in 2.5 Subaru swap.

[a57oval]

Hi All,
I now have about 25,000 miles on my swap. Just got back from a 19,400 mile trip from Seattle WA to The keys in FL and back with very few issues.

Nasty engine tick started about 1000 miles ago.
The engine:
2004 2.5 SOHC
NEW, not rebuilt short block with about 25,000 miles.
Rebuilt heads
All OEM Subaru components used in engine build including timing belt, tensioners,rollers, oil pump, head gaskets.
Subarugears 5 speed with OEM Subaru clutch components.
Small Car header.
Small Car oil pan with Small Car pick up tube.
OEM oil filter, Shell Rotella T6 5W40, perfect Oil analysis 16,000 miles ago.

Only happens on cold start up. Here's the weird part; sometimes it happens sometimes it doesn't. Never does it when engine has warmed up.

Video of tick:
https://www.youtube.com/watch?v=sdFR1ZOuPhw&feature=youtu.be

In addition to the tick listen to the much deeper sound at around the 2:00 minute mark where I move the camera from the center to the left then to the right of the engine.
To me the tick doesn't sound like piston slap. Does the deeper "knock" heard around the 2:00 mark sound like piston slap?
Doesn't sound like YouTube videos of rod knock.
Visually inspected the timing belt tensioner when cold started. Is not bouncing around. Checked mechanical timing. Looks right to me.
Can't find any crack in exhaust system or EGR pipe. Can't feel any leaks.
Suspecting a loose valve, I readjusted the valves with a cold engine. Very slight improvement.
Oil level kept between 4.5 and 5.0 quarts.
Sat for 5 days, I went and started it and the tick was so loud I turned it off. Sounded WAY worse than the video. Sounded like someone banging on a empty 55 gallon drum. That loud . Restarted it and it was much quieter, eventually diminishing to no noise.

Yes i know it is a Bay but there are many more Subaru swaps in the Vanagon forum, thus my posting here.

Got any ideas?
Thank you,
Peter

[MarkWard]

Disconnect one cylinder at a time while it’s making noise. If the noise subsides with one cylinder shut down, you found the offending cylinder. If the noise is consistent killing each cylinder, then you’ve got a problem likely with the valve train. Sorry I don’t click on links, so my suggestion is based on your description.
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[dobryan]

Maybe use a mechanics stethoscope or long screw driver to see if the ticking is isolated to one head or the other.
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'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

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[drj434343]

Sounds like a hydraulic lifter to me. At least on EJ22's, the oil can leak out and cause a nasty tick just like that that scares the hell out of you. Happened to me after letting the van sit for 4 months.

I'm not sure what year EJ25 you have or if it even has hydraulic lifters; I know they transitioned to solid lifters at some point, but might be worth investigating.

[skills@eurocarsplus]

2 things come to mind

you have a bad cylinder...sounds like wrist pin/rod knock

or you have a bad timing belt tensioner. I have seen even new Subaru ones collapse and let the belt slap around.

if you pull 1 plug wire at a time, it will isolate the cylinder. if the noise goes away, it's internal/lower end

what was done to the heads? rare, but high mileage Subaru heads have valve guides migration issues

you can drop the exhaust and see if you have a guide that looks like it's moving. that can explain the come-and-go nature of the noise.

it would run like straight up shit if it had a broken valve spring, which is unlikely from what I saw in the video
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[a57oval]

This is a great start. Thank you for all of your help.
Skills, I tried to address your points below:

you have a bad cylinder...sounds like wrist pin/rod knock
If this were the case wouldn't the sound occur at every startup? I have also tried to listen for a rod knock by holding the throttle up around 2500 rpm for 10 or 15 seconds then suddenly backing off the throttle and listening. I cant hear anything when I do that. Another thought would be to do another oil analysis. If a rod bearing were failing wouldn't the engine produce metal?  I would think this would show up in the analysis.

or you have a bad timing belt tensioner. I have seen even new Subaru ones collapse and let the belt slap around. 
I removed the small plastic cover off of the right side of the engine ( which would be Driver's side in the Subaru) and watched the timing belt and tensioner. I started the bus, it did not rattle, the timing belt ran smooth with no bouncing, and the tensioner did not bounce around. Could this fail in the random pattern that I am experiencing?

if you pull 1 plug wire at a time, it will isolate the cylinder. if the noise goes away, it's internal/lower end
Next time it rattles this is exactly what i will do.

what was done to the heads? rare, but high mileage Subaru heads have valve guides migration issues
The heads now have 140,400 miles on the castings. The re builder of the heads surfaced them, did valve guide seals, lapped the valves to the seats. He said the guides were within spec.

you can drop the exhaust and see if you have a guide that looks like it's moving. that can explain the come-and-go nature of the noise.
When you say a valve guide that looks like it is moving, what does that look like? Additional protrusion into the head? 

it would run like straight up shit if it had a broken valve spring, which is unlikely from what I saw in the video  
It runs awesome. Never hiccups. It does use a quart of oil every 3,000 miles which is a little disappointing being that I bought a new short block and had the heads rebuilt.

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Timing belt tensioner. When you have cover off are you able to press down on the tensioner with long screwdriver? If so I would try to see if it affects noise. Is it 2.2? What year?

[a57oval]

Timing belt tensioner. When you have cover off are you able to press down on the tensioner with long screwdriver? If so I would try to see if it affects noise. Is it 2.2? What year?
Jeez, that was stoopid on my part. 2004 2.5 SOHC. I amended my inquiry.
Great suggestion. I will try that the next time it rattles.
Peter

[ftp2leta]

Rod knock
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[Howesight]

Hi Ben:

Good to see you here again! I hope you are well and staying safe. We are hunkered down here in Vancouver and doing our very long list of "to do" items around the house and for me, on vehicles.

I see that Quebec has been hit hard by COVID, so all the Spring activities you folks normally look forward to after the long winter are all cancelled. For us, our winter was a bit more tolerable, so we have a bit less cabin fever.

Stay safe!
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'86 Syncro Westy SVX

[a57oval]

Hello Ben,
Rod Knock
If this is the case why would would the problem come and go? I would think that if it had a rod knock i would hear it all the time and the sound would be fairly consistent. Am i missing something?

[DirtyBlueVan]

If its not doing it warm, and not consistent its most likely a collapsed lifter IMO (not an expert). they can get gummed up. maybe run a quart of marvel mystery oil or something like that and see if you can get it cleaned out.
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1989 Syncro Westfalia 2.5 smallcar subie

[a57oval]

If its not doing it warm, and not consistent its most likely a collapsed lifter IMO ...
This engine does not have hydraulic lifters so i dont think that is it.

So here are 3 very short videos of a cold start I did this morning. Notice there is no nasty tick. And I dont hear anything odd. I would think if it were a rod knock it would be audible on cold start. Do you all agree?

https://www.youtube.com/watch?v=UmvVWWqZh-Q&feature=youtu.be

Close up of cylinders 1 and 3:
https://www.youtube.com/watch?v=tx7tzg83L8g&feature=youtu.be

Close up of Cylinders 2 and 4:
https://www.youtube.com/watch?v=sjGzXWcEB8s&feature=youtu.be

I am so confused,
Peter

[wesitarz]

I had a loud ticking with my 2.5 on cold start after a days highway drive to northern CA. With cold start the next morning it improved with driving and warm up. I was using 5W-30 oil. I see Rotella T6 is 5W-30. Try using a 10W-30 oil.

[DirtyBlueVan]

[Jake de Villiers]

Does it make that sound when you lift off the gas to change up to the next gear? When the wrist pin bushing is going, the first place you notice it is when unloading the piston between gears. While there is a load on it, cylinder pressure holds that joint together and keeps it quiet.
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[a57oval]

Does it make that sound when you lift off the gas to change up to the next gear? When the wrist pin bushing is going, the first place you notice it is when unloading the piston between gears. While there is a load on it, cylinder pressure holds that joint together and keeps it quiet.

While I have not done your exact procedure, the noise does not occur after the engine is warmed up. I have tried multiple time to listen for it when driving down the road and have never heard it. I did try to rev it to about 2500 rpm for about 10 to 15 seconds, then back off the throttle suddenly and listen for the noise as the engine decelerated. No rattle.
Also I never hear the rattle between shifts.

[Deberius]

Hi Peter,

I'm not a big specialist about Subaru engines. I owned a 2.5 Legacy GX 1999 with 125.000 miles on it (great car!). It also had minor issues like every other car (besides rust )

Just my experience:

It also had the piston slap in the morning. The colder it was, the longer the piston slap lasted. If it doesen't last for more then 20 sec. everything is fine. I never got rid of the slap, but I had a half way victory:

First, the pre owner installed wrong sparkplugs and one of them was not tightend correctly (half way loose).

Second was oil coming trough the valve cover gasket inside the Spark plug "tunnel" (a common proplem), so during the first revolutions one cylinder didn't had a spark...

Next I switched to an 5w-50 engine oil.

Third would be classic by checking valve clearence, you never know...

The result was, that the slap started below 50°F and lasted maximum 7 sec.

Further more it is always hard to tell from a video, made with a phone, or gopro, how the sound actually is in reality...

Piston slaps in subaru engines won't happen every time, because it depends on the position of the slapping cylinder(s) and valves before starting. But the sound in my case was quite similar...

Just for your search

Cheers Oliver (sorry for my german english )
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1990 Caravelle GL 2.1 MV syncro -> 1990 Multivan Syncro 2.3 MV

[a57oval]

Hi Oliver,
Thanks for responding to the thread. Your German English is a lot better than my English English.



First, the pre owner installed wrong sparkplugs and one of them was not tightend correctly (half way loose).
PLugs are OEM Subaru ordered per the VIN of the Vehicle from which the engine came. Torqued to spec.

Second was oil coming trough the valve cover gasket inside the Spark plug "tunnel" (a common proplem), so during the first revolutions one cylinder didn't had a spark...
Dont think this is my issue. Spark plug valleys are bone dry.

Next I switched to an 5w-50 engine oil.
I am using Shell Rotella 5w40. Same "cold" weight.

Third would be classic by checking valve clearence, you never know... Smile
Yup. That was my first thought. So I did a valve adjust and experienced a very small change in the noise. Less than a 5% change I would say.

Further more it is always hard to tell from a video, made with a phone, or gopro, how the sound actually is in reality.
Agreed.

Still stumped. I am thinking the next step will be to send in an oil analysis and see if there is any metal or any sort in the oil. My previous analysis, about 22,000 miles ago, was perfect. Going to be interesting to see if there is a difference.
Anyone have input?
Peter

[Deberius]

Good luck!
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1990 Caravelle GL 2.1 MV syncro -> 1990 Multivan Syncro 2.3 MV