blew my si

[mash]

Well... 50 to 70 could be anywhere between a bit under redline to nearly 9000 RPM. If you go to the dealer, they'd see if you have an over rev code in your ECU.

There's been a few here and there, as there are with all manual cars. If it survived the event and a valve didn't float and bend as it smacked a piston, it was probably ok and may very well have not contributed to the later failure.

Was your engine warmed up when you did the 2 step when the failure happened?

My engine was warmed up and it was right after i did a pull. ( i did bounce off the the rev limiter ). It cost around 4k to rebuild the engine or over 10k to get a new engine. I believe it would be better to just find a used engine and have it installed.

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[gtman]

So you did a hard pull to redline and then right after you launched the car with the two step. And it just "blew" and lost power?

 

[mash]

So you did a hard pull to redline and then right after you launched the car hard? And it just "blew" and lost power?

Pretty much.

 

[SCOPESYS]

My engine was warmed up and it was right after i did a pull. ( i did bounce off the the rev limiter ). It cost around 4k to rebuild the engine or over 10k to get a new engine. I believe it would be better to just find a used engine and have it installed.

Plenty of good, hardly used 2018 SI motors around on Totaled cars, some with less than 1000 miles on them. Will probably cost more in labor than materials.

Time to find a good, reliable mechanic, that will not take you for ride.

 

[jred721]

So you're saying you blew an engine even though it was warmed up. That's pretty disappointing to hear. You'll get a new engine easily though.

 

[charleswrivers]

The engine has low compression and the car also will not go into boost. I was told something about a valve being burnt. There is also blow by oil by the manifold. Smoke and bad smell.

Not to jump to conclusions... but if the only issue is a single valve/spring/guide... it could cause all of that. Before you jump to a new engine, I wonder if all your problems could be solved by getting a head of a junker and swap or have the valve/spring/guide done with the seat cleaned up. Before I jump for a $4k rebuild or $10k replacement or whatever-it-was... I'd verify it's as bad as what it's being made out as.

One valve not seating for one reason or another can cause oil blowby. Compression to be bad. The car to not run right. That doesn't = need a whole new engine or rebuild.

 

[charleswrivers]

@mash ... I did a quick look and a new head can be bought as an assembly for about $750. I would assume that it comes with everything, minus gasket and bolts.

I've pulled a head from a junkyard when a friend set his timing wrong and bent all his valves (always bar over and feel for resistance before you crank!!!). Cost was $50 from a u-pull. These engines haven't become plentiful yet because the car is new. There may still be sources.

I don't want to get your hopes up too much... but the 1) burned valve 2) burns oil 3) low compression doesn't immediately mean the engine is bad. People are quick to replace rather than fix... even at the dealer level. If they're not looking at a warranty repair due to a not stock car with a possible overrev, they're maybe looking to just do a sure thing that would give them profit... fix the engine. $4k for a head replacement is still wildly expensive if that's what they're planning. I pulled the head in a morning, including a 45 minute drive one-way to the junk yard, armed with my snazzy electric torque wrench and some other random tools... we broke for lunch, and had the head swapped and the car running before dinner time. This was after doing a compression check and pulling the old head a day earlier when I spoke to him and realized he self-destructed his head when he completely f'ed up setting the timing. It is not an amazingly difficult thing to do and a head is heavy but an adult of average strength can lift it and set it in place with a bit of difficulty. A friend is highly recommended.

Repairing the head may be a touch harder. At the time, I decided that it would actually be cheaper to get a used head than buy all new valves and lap the seats. I hadn't (and still haven't) pulled valves/springs and cleaned up a valve seat since I was about 16 or 17 and was made to do it on a small engine. That was not a difficult task then... but the cost of the van is themselves pretty well equalled the cost of the head... and there was less work involved and no wait time to get a head vs order the valves and all that jazz.

Again... it could all be terrible. Maybe it all does need to go.

... or you could have some failure isolated in the head that has done nothing to the bottom. Make sure you're not being taken for a ride even though you're in a bad spot with your car. If someone says a valve issue has broke the engine and the whole thing needs to be replaced but can't say what is wring with the bottom, find a new mechanic. Compression will be bad with a valve that won't seat... that doesn't mean there's any issue with the piston/rings/cylinder.

You can hit the piston with the valves and other than the top of the pistons being 'kissed' that doesn't mean anything but the valves/head need work.

Good luck! Keep us posted!

 

[mash]

I am responsible for this so i will keep you all updated with this costly repair

Not to jump to conclusions... but if the only issue is a single valve/spring/guide... it could cause all of that. Before you jump to a new engine, I wonder if all your problems could be solved by getting a head of a junker and swap or have the valve/spring/guide done with the seat cleaned up. Before I jump for a $4k rebuild or $10k replacement or whatever-it-was... I'd verify it's as bad as what it's being made out as.

One valve not seating for one reason or another can cause oil blowby. Compression to be bad. The car to not run right. That doesn't = need a whole new engine or rebuild.

@mash ... I did a quick look and a new head can be bought as an assembly for about $750. I would assume that it comes with everything, minus gasket and bolts.

I've pulled a head from a junkyard when a friend set his timing wrong and bent all his valves (always bar over and feel for resistance before you crank!!!). Cost was $50 from a u-pull. These engines haven't become plentiful yet because the car is new. There may still be sources.

I don't want to get your hopes up too much... but the 1) burned valve 2) burns oil 3) low compression doesn't immediately mean the engine is bad. People are quick to replace rather than fix... even at the dealer level. If they're not looking at a warranty repair due to a not stock car with a possible overrev, they're maybe looking to just do a sure thing that would give them profit... fix the engine. $4k for a head replacement is still wildly expensive if that's what they're planning. I pulled the head in a morning, including a 45 minute drive one-way to the junk yard, armed with my snazzy electric torque wrench and some other random tools... we broke for lunch, and had the head swapped and the car running before dinner time. This was after doing a compression check and pulling the old head a day earlier when I spoke to him and realized he self-destructed his head when he completely f'ed up setting the timing. It is not an amazingly difficult thing to do and a head is heavy but an adult of average strength can lift it and set it in place with a bit of difficulty. A friend is highly recommended.

Repairing the head may be a touch harder. At the time, I decided that it would actually be cheaper to get a used head than buy all new valves and lap the seats. I hadn't (and still haven't) pulled valves/springs and cleaned up a valve seat since I was about 16 or 17 and was made to do it on a small engine. That was not a difficult task then... but the cost of the van is themselves pretty well equalled the cost of the head... and there was less work involved and no wait time to get a head vs order the valves and all that jazz.

Again... it could all be terrible. Maybe it all does need to go.

... or you could have some failure isolated in the head that has done nothing to the bottom. Make sure you're not being taken for a ride even though you're in a bad spot with your car. If someone says a valve issue has broke the engine and the whole thing needs to be replaced but can't say what is wring with the bottom, find a new mechanic. Compression will be bad with a valve that won't seat... that doesn't mean there's any issue with the piston/rings/cylinder.

You can hit the piston with the valves and other than the top of the pistons being 'kissed' that doesn't mean anything but the valves/head need work.

Good luck! Keep us posted!

thank you for this amazing info. I will gladly keep updates.

 

[Green82]

Interesting, was it a bad one? (i.e. way past the rev limit). If you know the initial speed/gear you shifted to, we can figure out the approximate RPM. Was there any issues you noted between the misshift and the engine failing?

I appreciate you sharing. An Si engine and with that specific tune and the scenario overall are good data points for those of us to have.

Though the lead up is different and one wasn't an Si, this is the second failure using 2 step I've read about in the last week or so.

https://www.civicx.com/threads/blew-my-engine-on-a-4krpm-2-step-cold-start.33860/page-4

I missed shifted once doing 80 mph and went from 5th gear to 2nd this was done during the summer

 

[charleswrivers]

I missed shifted once doing 80 mph and went from 5th gear to 2nd this was done during the summer

That'd be a pretty decent overrev. You made a thread about it with your engine being ok, right?

 

[Green82]

That'd be a pretty decent overrev. You made a thread about it with your engine being ok, right?

No never made a post but engine was fine think I hit the clutch fast enough.

 

[latole]

I don’t know much about cars but i have some knowledge. I also had 1 miss shift a week before it blew.

It is a hard way to learn, sorry for you.

 

[NoHonor937]

exactly why his engine blow then? If it was warmed up then it should’ve been fine....oh wait never mind. 2 step blew his engine along with ktuner!

 

[krees]

exactly why his engine blow then? If it was warmed up then it should’ve been fine....oh wait never mind. 2 step blew his engine along with ktuner!

With great power comes great responsibility. Ktuner didn't blow his engine, his right hand and foot did.

OP: Hope you get it sorted and sorry that it happened. Failure is the best teacher though so make sure to learn from this.

 

[HotPaperPlate]

Sorry OP, I blew my motor 2 weeks ago too. 18k miles on the SI motor, drove to the gas station. filled up, approached the on-ramp (rush hour traffic) 2nd gear to 3rd gear (low/normal rpms) at 20-25mph and slung a rod through the block. Found a used 11K miles SI Motor last week, my mechanic will update me once he drops the motor etc.

Oil changed every 5k
93 Octane gas with every fill-up
Drop-in Dry air filter + Hardrace RMM
TSP 1 .49-.59 k.control
Mostly highway miles

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