Jump to content
SAU Community

Recommended Posts

Hey people im hoping for some help here, i took my skyline r33gtst to get minor work done and just its regular check up.. The mechanic told me he noticed the car was miss- firing, ( bare with me as im not all that knowledge based with cars) he put my hand up to a small pipe that was blowing out air in small bursts, then put my hand up to the exhaust.. I couldnt quite understand what he was on about, but basicaly told me one of my piston rings is cracked or broked meaning my car is running on 5 cylinders, not 6. He told me the engine has to be pulled out and needs new pistons... Im just wondering if theres an alternate explanation for what hes telling me is wrong, or is there a way i can test my car to get a 100% notibility with what the problem actualy is or if theres a problem at all, i personaly didnt know anything was wrong with my car before he told me it needs major work done, it runs beautifuly. So any feed back would be greatly appreciated, cheers

LOL - go to a different mechanic. if it doesn't misfire under boost or load, then it's unlikely there is an issue (especially if you haveen't noticed anytihng as the driver). too hard to diagnose anything like this over a keyboard...

does it blow smoke out of the oil filler if you remove while idling?

Does your car sound like a WRX? If so, then yes, you are running on 5 cyl. Otherwise it seems as though the mechanic may have misdiagnosed the problem; a problem that you never noticed beforehand - especially if you mentioned the car runs beautifully.

The small bursts of air have been associated with piston ring failure but as I mentioned above, the dead giveaway is the WRX sound (going from my experiences). I would take it to another mechanic (don't say anything about piston rings) or a friend who knows engines.

Whats the best way to notice if my car is miss firing? i dont exactly hoon around in the car all that much im a fairly casual driver, so if i put my foot down what sort of reaction should i be looking for? I havnt noticed any smoke coming out of it, ive parked it up somewhere secure and safe until i figure out whats wrong with it. Mechanic said if i continue to drive it around it will eventualy start spitting oil and cause more damage... Kinda annoying coz ive just had the head reconditioned due to the timing belt snapping which was a 3 grand operation, now he tells me the bottom needs doing with new pistons... I just wana make sure hes not pulling my leg coz i dont know a whole lot about cars.

LOL - go to a different mechanic. if it doesn't misfire under boost or load, then it's unlikely there is an issue (especially if you haveen't noticed anytihng as the driver). too hard to diagnose anything like this over a keyboard...

does it blow smoke out of the oil filler if you remove while idling?

Remove the OIL filter while idling?!?!?!?

Did you mean the air filter?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • As discussed in the previous post, the bushes in the 110 needed replacing. I took this opportunity to replace the castor bushes, the front lower control arm, lower the car and get the alignment dialled in with new tyres. I took it down to Alignment Motorsports on the GC to get this work done and also get more out of the Shockworks as I felt like I wasn't getting the full use out of them.  To cut a very long story short, it ended up being the case the passenger side castor arm wouldn't accept the brand new bush as the sleeve had worn badly enough to the point you could push the new bush in by hand and completely through. Trying a pair of TRD bushes didn't fix the issue either (I had originally gone with Hardrace bushes). We needed to urgently source another castor arm, and thankfully this was sourced and the guys at the shop worked on my car until 7pm on a Saturday to get everything done. The car rides a lot nicer now with the suspension dialled in properly. Lowered the car a little as well to suit the lower profile front tyres, and just bring the car down generally. Eternally thankful for the guys down at the shop to get the car sorted, we both pulled big favours from our contacts to get it done on the Saturday.  Also plugged in the new Stedi foglights into the S15, and even from a quick test in the garage I'm keen to see how they look out on the road. I had some concerns about the length of the LED body and whether it'd fit in the foglight housing but it's fine.  I've got a small window coming up next month where I'll likely get a little paint work done on the 110 to remove the rear wing, add a boot wing and roof wing, get the side skirt fixed up and colour match the little panel on the tail lights so that I can install some badges that I've kept in storage. I'm also tempted to put in a new pair of headlights on the 110.  Until then, here's some more pictures from Easter this year. 
    • I would put a fuel pressure gauge between the filter and the fuel rail, see if it's maintaining good fuel pressure at idle going up to the point when it stalls. Do you see any strange behavior in commanded fuel leading up to the point when it stalls? You might have to start going through the service manual and doing a long list of sensor tests if it's not the fuel system for whatever reason.
    • Hi,  Just joined the forum so I could share my "fix" of this problem. Might be of use to someone. Had the same hunting at idle issue on my V36 with VQ35HR engine after swapping the engine because the original one got overheated.  While changing the engine I made the mistake of cleaning the throttle bodies and tried all the tricks i could find to do a throttle relearn with no luck. Gave in and took it to a shop and they couldn't sort it. Then took it to my local Nissan dealership and they couldn't get it to idle properly. They said I'd need to replace the throttle bodies and the ecu probably costing more than the car is worth. So I had the idea of replacing the carbon I cleaned out with a thin layer of super glue and it's back to normal idle now. Bit rough but saved the car from the wreckers 🤣
    • After my last update, I went ahead with cleaning and restoring the entire fuel system. This included removing the tank and cleaning it with the Beyond Balistics solution, power washing it multiple times, drying it thoroughly, rinsing with IPA, drying again with heat gun and compressed air. Also, cleaning out the lines, fuel rail, and replacing the fuel pump with an OEM-style one. During the cleaning process, I replaced several hoses - including the breather hose on the fuel tank, which turned out to be the cause of the earlier fuel leak. This is what the old fuel filter looked like: Fuel tank before cleaning: Dirty Fuel Tank.mp4   Fuel tank after cleaning (some staining remains): Clean Fuel Tank.mp4 Both the OEM 270cc and new DeatschWerks 550cc injectors were cleaned professionally by a shop. Before reassembling everything, I tested the fuel flow by running the pump output into a container at the fuel filter location - flow looked good. I then fitted the new fuel filter and reassembled the rest of the system. Fuel Flow Test.mp4 Test 1 - 550cc injectors Ran the new fuel pump with its supplied diagonal strainer (different from OEM’s flat strainer) and my 550cc injectors using the same resized-injector map I had successfully used before. At first, it idled roughly and stalled when I applied throttle. Checked the spark plugs and found that they were fouled with carbon (likely from the earlier overly rich running when the injectors were clogged). After cleaning the plugs, the car started fine. However, it would only idle for 30–60 seconds before stalling, and while driving it would feel like a “fuel cut” after a few seconds - though it wouldn’t fully stall. Test 2 – Strainer swap Suspecting the diagonal strainer might not be reaching the tank bottom, I swapped it for the original flat strainer and filled the tank with ~45L of fuel. The issue persisted exactly the same. Test 3 – OEM injectors To eliminate tuning variables, I reinstalled the OEM 270cc injectors and reverted to the original map. Cleaned the spark plugs again just in-case. The stalling and “fuel cut” still remained.   At this stage, I suspect an intermittent power or connection fault at the fuel pump hanger, caused during the cleaning process. This has led me to look into getting Frenchy’s fuel hanger and replacing the unit entirely. TL;DR: Cleaned and restored the fuel system (tank, lines, rail, pump). Tested 550cc injectors with the same resized-injector map as before, but the car stalls at idle and experiences what feels like “fuel cut” after a few seconds of driving. Swapped back to OEM injectors with original map to rule out tuning, but the issue persists. Now suspecting an intermittent power or connection fault at the fuel pump hanger, possibly cause by the cleaning process.  
×
×
  • Create New...