FRS Rod Knock - Estimated Repair Costs
 

Hi. I have a 2015 AT FRS and have been hearing rod knock from my engine. I wanted to get an idea of what I can expect to pay for the repairs. Any mechanics here or people who've had it done that can chime in? (Please also let me know which state you got the work done in since cost can vary.)

Is it cheaper to repair it or do an engine swap? How much can I expect to pay total for an engine swap? Thanks!

These engines are noisy and make strange sounds. The high pressure fuel pump sounds like a rod knock.

If you are paying someone to do the work the lease expensive is a used engine swap.

Replacing with a used engine is the cheapest by a bit
Replacing with a new shortblock is more but you don't have to worry about the used engine going out again. Range would be 5-8-10 K depending on your decision.

Thanks for the replies so far. If any others want to chime in, please do so. More info, the better.

FWIW, the interval of the knocking sounds is somewhat consistent but the frequency (higher vs. lower pitch sound) is not as consistent. It fluctuates from higher to lower back to higher. (Don't know if that helps identify a rod knock vs. high pressure fuel pump problem)

Sounds like I may be better off selling the car since I'm not attached to it.

You'll have a hard time selling it however sometimes people are willing to buy these cars and do the work themselves as long as the price reflects the need for a new engine.

Come to think of it, the sound (although much quieter) began after the dealership resealed the front timing cover 1.5-2 years ago. Could that job create the rod knock issue? Problem is the dealership won't own up to it and the car is no longer under warranty. I should have brought it right back to them assuming it is rod knock.

How did you conclude the sound is a rod knocking?

Did you get a second opinion from a mechanic about that sound?

If you would post a video/audio of the sound, we could give our opinion.

Since your car is an AT, some have reported that a vacuum pump located on the passenger side of the engine, towards the back can give a "knocking sound". You may wish to give a listen back there.

Good luck!

I concluded the sound is rod knocking by researching online and hearing various clips from other FR-S owners on Youtube. I did not get an official diagnosis but will have it checked out. I wanted to do preliminary research and get an idea of what I can expect to pay for a repair/decide if it's worth it to put more money into my car.

Mine

https://youtu.be/zbd4DzAlW4c

Thanks Tommy.

It actually sounds a lot like this... (specifically the sound you hear more clearly at the 0:09 and 0:19 marks) If the problem is one in the same, looks like it is the vacuum pump.

https://www.youtube.com/watch?v=qIlHnd39iHU

humfrz, the sound does seem to be coming from the passenger side. if it is the vacuum pump, i'm thinking that's a significantly cheaper job. i wonder if it's something i can tackle on my own. i'll need to see if a DIY exists on Youtube.

IIRC if that is the vacuum pump it's fine so its free.

haha. thanks. i would like to fix it. :-)

Wait, you heard a noise you thought was rod knock and you drove it for 2 years with it?

I didn't think it was anything serous until recently. The sound has gotten louder more recently.