Hi Acura Lovers/DIYers

here is interesting case if anyone can help. I have 2013 Acura RDX base FWD with 230K miles that had slight misfire in Cylinder 4 when I bought it as project car. As far as history of this is concerned, timing belt was broken on highway and last owner took a chance by just replacing the timing belt but when it was turned on, there was slight misfire and lack of acceleration and owner thought to get rid of it. So before buying I had it presale inspection done at Acura Dealer and recommendation was to change engine. So I knew what I was getting into...so no complaints there as last owner told everything and gave the receipts of the timing belt change done.

After getting it, as a DIY I started with basics, with slight hopes of reviving it before I go for obvious i.e. engine swap. Changed spark plug(NGK amazon), coil(used ebay good condition) and injector (used ebay). Good part is that after hitting these basics the misfire was gone for about 300 miles and then it came back. In terms of acceleration it has little lag but lot better than what it was before.

So now I have taken apart the front cylinder head and was thinking to have the bent valves fixed and reassemble it. So if it works out as planned, hope I revive the engine but then there is another thought, if it doesn't work then I was thinking to swap the engine. So if I go for engine swap, in that case, can we use 2016 to 2018 Acura RDX Engine Motor into this 2013 Acura RDX or I need to stick to 2013-2015 Acura RDX engine motor only? As in terms of facelift for 2016-2018 Acura RDX there is not much difference in terms of horsepower 279 hp against 273 hp but not sure if it would fit or not so if anyone has this deep DIY knowledge or any honda/acura tech in this form it would be helpful. Also cost wise...2016 -2018 used engine motors are cheaper as compared to 2013-2015 that's factor I am considering newer model engine if it fits technically .

Thanks in Advance

 

If everything works well with new spark plugs, then the valves are not bent, and you just need to abandon the VCM with an VCM muzzler. A new engine is not needed.

 

thanks for the response. I'll try that too after reassembling if the issue is not gone. I still need to have cylinder head pressure tested.

 

updating my own thread for the benefit of future DIYs....

so here is sequence of events in terms of timeline...

- Got this project SUV back in June, 2022
- tried with obvious "parts gun" as we call it trying to defy the obvious one until June, 2023 then finally took apart the front cylinder head
- got back the courage to give it a go again in July, 2025 meanwhile almost 2 years, didnt get time/kept on delaying or whatever u say it... debated engine swap/Vs fix to learn things. meanwhile also tried to look around for good cylinder head/Machine shops in Northern Virginia to make sure they know what's required/other words validating my cost metrics revive this old cylinder head or buy the remanufacture from eBay...even I got one from ebay for about 350 which I found to be remanufactured as valve sheets were cut to make it fit oversized valves, didn't feel right so sent it back
- so finally found a good old machine shop with experienced folks to fix this existing front cylinder head(4,5,6), found 3 bent valves and broken valve springs...
- With revived cylinder head, during installation...to rule out any issue with back cylinder head(1,2,3) did the leak test for intake valve, exhaust valves and then compression test before putting the front cylinder back.
- when it came down to put it back took help of old friend/retired Honda Master tech mechanic/mentor and luckily it all came back nicely and no more misfires now!
- why I went through all this, so...didn't like throwing this reliable engine(no oil loss even after 230K already on this, mostly highway though) just because of bent valves...believe in repair instead of replace and of course learning project it as it was anyway throwaway and nothing worse could have happened..

lessons learned as DIYs..
- first of all, dont start any such DIY project, until you have spare vehicle, garage or drive way for long term parking spot to come back next time and start where you left last time
- if you take it apart, make sure you take picture as you go along and put back/thread back the bolt/nut(as I did) wherever possible on the same spot so you don't loose those nuts/bolts and if that's not possible then put these individual part with their corresponding nut bolts in those sandwich Ziplock bags as you don't know how long it might take to put it back and you can find all relevant part together
- don't try to finish it in a day, take your time as saying goes...don't rush or you'll be late(by loosing critical bolt in engine area/slipped bolt/cross thread/making silly mistakes etc). Your mind/body will signal you so It's part of process to call it a day and start fresh next day or next weekend even next month is fine!!
- I didnt put those nitty/gritty of bolt/torque as if you're thinking of taking apart engine... you'll know/find all those anyhow on youtube but important part is keep yourself motivated, and with this long timeline of mine I hope you have enough motivation of bringing it to finishing line in next 2-4 months once you restart!.

Happy DIYs!!