Burned valve or what? Another misfire thread

Hey all, thanks for reading in advance, learned a ton from this forum. Help/Advice needed. 2007 Spec B @ 150000miles. Stock.

So finally decided to get off my ass and get my Spec B e-tuned. During the tuning process everything was going well, not a lot of knock, logs looked good, until the final tune was sent and I developed a misfire (at idle and part throttle) Cyl #1. Note - I had not had any misfire codes before this in the car - I am not blaming the tune - but I don't know enough about it to say either way, all I can say is I hadn't had this code before the tune, and it showed up during.

Now troubleshooting - I swapped coils - no luck, misfire stayed in Cyl #1. Misfire only at idle and low throttle. Otherwise seemed to run fine (No WOT since I've had this code). Rented compression tester and today Got readings of 60-90psi on Cyl #1 warm (didn't do other cylinders as they're a bitch to get to, I'm sick and this was my problem cylinder). It showed 60 psi 3 times, and 90 PSI once - why different readings? Also I've never done a compression test before and I think I did it right (screwed into spark plug hole, cranked engine when warmish,foot on throttle to floor).

So my question is - On a 07, with 150kmi on it, thats lived in salt country (though the underbody and body have always been rust proofed and are in decent shape) that also likely needs a suspension rebuild (stock since new, only one shock changed by PO) is it really worth it to rebuild the heads - assuming that all I need to do? I do not have time to do it myself (not even sure if I did I would want too) and I can afford to rebuild them, but I'm wondering if its even worth it.

Pics of Compression tester and spark plug (does this look like deposits from burned valve?) - Anything else it could be?

See pics hosted on google. Can't upload them - its failing and won't accept the google link.

https://drive.google.com/open?id=1GTv9eSrqQxDMUbm3ZZszXCfqjwYa5rAJ

https://drive.google.com/open?id=1l9i12zPIDWFDL9T14PBwhZF3VkNwBEep

It is a Spec B, so it has the good 6mt.

At 150,000 miles, if you rebuild the heads...and not the bottom end or put a ej257 short block in. Some say that with rebuilt heads, the rings will be the next to go.

What can you find for a another car to take it's place ?

Did you buy this car new or used ?

How much do you enjoy driving it ?

If your the type that feels, "its just car" then move on to another car. If your know what you got, then may be look at spending $6-7000 and keep it.

Have you figured it out yet?

My XT has the same symptoms on the same cylinder. Broken ringlands in the piston. 267,000 KMs on it, all stock.

Edit: pulled the head off and the piston out this last weekend. Piston had no broken ringlands but the control rings were seized in. Loss of compression was from both exhaust valves having zero clearance on the cam. Trying to figure out the reason to prevent it happening again.

The reason may be in your fourth sentence.

At that mileage, about half-way between the first and second timing belt change interval, the valve clearance can be expected to be quite far out if it was never corrected. Exhaust is the worst as the heat and pounding causes the valve head recede into the pocket.

The 'fix' is to check and correct valve clearance during timing belt service. Some on this forum have reported doing it with the engine installed. Not particularly fun. Having some sort of lift so you can work standing under the car might make it almost enjoyable.

BTW, I tore my 2005 LGT engine down for 'broken ringlands' and found exactly what you report: ringlands were fine but oil control rings hopelessly seized. It had been like that for a long time. The final straw was a big hole in one of the exhaust valves that meant it could no longer be run. The build is documented HERE.

Have you figured it out yet?

My XT has the same symptoms on the same cylinder. Broken ringlands in the piston. 267,000 KMs on it, all stock.

 

Edit: pulled the head off and the piston out this last weekend. Piston had no broken ringlands but the control rings were seized in. Loss of compression was from both exhaust valves having zero clearance on the cam. Trying to figure out the reason to prevent it happening again.

Thanks for the Link! Looks like we had suffered from the same gremlins.

I from the video of yours running I would have sworn you had spun a connecting rod bearing. Mine ate an exhaust valve (on cyl 4) like yours did 27,000 miles ago (18 months ago). I had the heads rebuilt at that time. So now with cylinder 1 sinking in the exhaust valves my question is was that from the excessive oil blowby? Or the head job I just had didn’t cut the seats or grind the valves properly?

My block looked like yours. Didn’t show much for wear but being pressure plate bored to 99.75.

I tried searching here for seized oil control rings with little luck. Any idea on how common that is on these engines? Causes? Or solutions to keep them clean? My engine is being rebuilt with Wiseco Forged pistons and the builder claims he has never seen those come back with seized rings, possibly due to the huge expansion compared to stock cast pistons.

Had my builder tear down the shortblock and examine for other problems. Looks like the previous owner suffered a headgasket leak and then drive it with coolant in the oil. Lots of wear on the bearings and journals. Old crank can be turned down but he said he wouldn’t trust using it in another turbo engine. The connecting rod bearings were in the verge of spinning and had zero squish left in them. So had I not torn it out for the valves and rings it would have came out soon for bearings. I bought the car at 78,000miles and 168,000miles now so it did last a little while.

I also found my replacement turbo from the last build came back without a restrictor pill. Been running 7 pounds boost for the last year. Have a Perrin EBCS ordered.

I was paranoid the valves were burning from lean conditions from the injectors. Had those tested Locally before cleaning and they were good. Since been cleaned and as I sent in 5, I have a matched set of 4 to go back in all within 1.2% of each other.

I had checked at the Calgary dealer for a replacement short block. All I can get is a rebuilt for $2800 plus $1500 core. My builder warned me the rebuilds he has seen from there are only lasting 50,000kms and they like to keep your core fee as they find reasons to discount the value of your returned core. Rebuilding the old one with a new crank, line bore the old case and forged pistons for the price the short block rebuild at the dealer.

-30C here now and waiting for parts to arrive.

A few comments for now.

Don't sweat the new crank. They are consumables due to the tight main bearing specs and the combined out of round issues with the base bores. You'll save nothing by refurbishing yours and then you have use oversize shells. If you can afford a line bore, and have someone equipped to do it, then maybe that is a good idea. It is not quite as simple as on a normal engine because you have to cut the case halves and then what do you do with the main seal pockets and whatnot? I just did some mix 'n match with a set of STD and a set of +0.001 shells and got pretty close on the clearances.

Resizing the rods is simple and standard. Have them press in and size new bushes at the same time. Sounds like your builder has all this under control. If you weren't going aftermarket pistons, it would make a lot of sense to buy the factory short block and skip right past all this stuff.

I don't know why my oil control went south. Maybe just the age (200K MILES), non-synthetic oil, severe service by previous owner. Who knows. Still, it ran like a champ and probably would have for some time if I had adjusted valves and continued to pour oil in.

You can make a bunch of restrictor pills of various sizes from mig welding tips. Specs are somewhere on this site.

Thanks for the Link! Looks like we had suffered from the same gremlins.

I from the video of yours running I would have sworn you had spun a connecting rod bearing. Mine ate an exhaust valve (on cyl 4) like yours did 27,000 miles ago (18 months ago). I had the heads rebuilt at that time. So now with cylinder 1 sinking in the exhaust valves my question is was that from the excessive oil blowby? Or the head job I just had didn’t cut the seats or grind the valves properly?

My block looked like yours. Didn’t show much for wear but being pressure plate bored to 99.75.

I tried searching here for seized oil control rings with little luck. Any idea on how common that is on these engines? Causes? Or solutions to keep them clean? My engine is being rebuilt with Wiseco Forged pistons and the builder claims he has never seen those come back with seized rings, possibly due to the huge expansion compared to stock cast pistons.

Had my builder tear down the shortblock and examine for other problems. Looks like the previous owner suffered a headgasket leak and then drive it with coolant in the oil. Lots of wear on the bearings and journals. Old crank can be turned down but he said he wouldn’t trust using it in another turbo engine. The connecting rod bearings were in the verge of spinning and had zero squish left in them. So had I not torn it out for the valves and rings it would have came out soon for bearings. I bought the car at 78,000miles and 168,000miles now so it did last a little while.

I also found my replacement turbo from the last build came back without a restrictor pill. Been running 7 pounds boost for the last year. Have a Perrin EBCS ordered.

I was paranoid the valves were burning from lean conditions from the injectors. Had those tested Locally before cleaning and they were good. Since been cleaned and as I sent in 5, I have a matched set of 4 to go back in all within 1.2% of each other.

I had checked at the Calgary dealer for a replacement short block. All I can get is a rebuilt for $2800 plus $1500 core. My builder warned me the rebuilds he has seen from there are only lasting 50,000kms and they like to keep your core fee as they find reasons to discount the value of your returned core. Rebuilding the old one with a new crank, line bore the old case and forged pistons for the price the short block rebuild at the dealer.

-30C here now and waiting for parts to arrive.

Looks like we kind of hijacked your thread here.

As for your questions. The plug looks pretty normal to me. The picture is not great, but it doesn't look oily or physically damaged. I didn't have much luck getting a reliable compression test with the motor in the car either. I really don't know what's up with that. Maybe I was not able to get the throttle plate properly open. If you have a major problem with a cylinder it would probably show up. I found better results with a leak down test, but then with the motor out and all.

My car was a New Hampshire import. Also rust belt. If you decide to do the suspension, expect every bolt to break and most to be a major hassle to get out. I'm at the point now that before I do any suspension work, I make sure I can get replacement bolts locally.

Hey all, thanks for reading in advance, learned a ton from this forum. Help/Advice needed. 2007 Spec B @ 150000miles. Stock.

 

So finally decided to get off my ass and get my Spec B e-tuned. During the tuning process everything was going well, not a lot of knock, logs looked good, until the final tune was sent and I developed a misfire (at idle and part throttle) Cyl #1. Note - I had not had any misfire codes before this in the car - I am not blaming the tune - but I don't know enough about it to say either way, all I can say is I hadn't had this code before the tune, and it showed up during.

 

Now troubleshooting - I swapped coils - no luck, misfire stayed in Cyl #1. Misfire only at idle and low throttle. Otherwise seemed to run fine (No WOT since I've had this code). Rented compression tester and today Got readings of 60-90psi on Cyl #1 warm (didn't do other cylinders as they're a bitch to get to, I'm sick and this was my problem cylinder). It showed 60 psi 3 times, and 90 PSI once - why different readings? Also I've never done a compression test before and I think I did it right (screwed into spark plug hole, cranked engine when warmish,foot on throttle to floor).

 

So my question is - On a 07, with 150kmi on it, thats lived in salt country (though the underbody and body have always been rust proofed and are in decent shape) that also likely needs a suspension rebuild (stock since new, only one shock changed by PO) is it really worth it to rebuild the heads - assuming that all I need to do? I do not have time to do it myself (not even sure if I did I would want too) and I can afford to rebuild them, but I'm wondering if its even worth it.

 

Pics of Compression tester and spark plug (does this look like deposits from burned valve?) - Anything else it could be?

 

See pics hosted on google. Can't upload them - its failing and won't accept the google link.

https://drive.google.com/open?id=1GTv9eSrqQxDMUbm3ZZszXCfqjwYa5rAJ

https://drive.google.com/open?id=1l9i12zPIDWFDL9T14PBwhZF3VkNwBEep