Jump to content
SAU Community

Recommended Posts

Man these RB engines are strong! The story goes...

Had it tuned Sat morning. All the air/fuel ratios were right and it made good power for stock turbo and cooler - a tad under 260rwhp.

It was a beautiful day and after having a bite to eat - my arm was twisted by a certain whore expert to go for a drive so we decided to drive up to Chittering...

After a gentle cruise up the freeway and a meander up towards the pine plantation near Wanneroo raceway, we turned off toward Great Northern highway and started passing some slower cars (which just happened to be all of them:D).. After a nice run I was onto the final straight and doing some good revs in 5th when something let go and I lost power... "hmm" I thought.. "wonder whats wrong?"...

We pulled off - inspected my engine which seemed to have a slight miss, decided the plugs had finally given up and decided to continue on and pick up some new plugs on the way home.

After a nice drive out to Chittering, back via Joondalup and through to my place in West Perth, everything was running ok with the exception of a slight miss.. My baby idled itself down in the garage and the whore expert and I went to work to replace the plugs...

What I saw next nearly gave me a heart attack... Somehow numer 5 plug had lost most of the hook over the electrode.. it just seemed to have melted away... "hmm.." I thought "wonder what the others are like.."

Number 3 was the next casualty. All I can say is that it had been obliterated... the hook over the electrode was completely missing and the electrode itself looked like it had suffered some sort of explosion as it was missing down to about 10mm inside the plug...

Panic stations were manned and calls were made.. I ended up replacing the plugs and turning it over.. Everything ran ok with a slight miss at idle - nothing more.. I let it be and decided to limp it up to a garage today...

Enter the compression test this afternoon. I would definitely recommend the Ultratune in Warwick. Dave the mechanic who works there is an absolute champ..Anyway - I digress.. So we pulled out the plugs (that were quite white) and attempt to do a dry compression test and it turns out his new guage is broken. Never fear, you could actually hear the difference between the compression in the other cylinders to number 3 cylinder. Then we try a wet compression test and it seems to come up ok. So we bolt everything back together and do an emmissions test on it. This showed excess fuel/oil which would indicate a tired engine. While it was idling, there was an arcing noise coming from under the plastic cover over the coils which seemed to coincide with the missing.

All of this tells me a few things:

1. The white plugs (100kms old) tells me that it's running lean

2. The wet compression test tells me that number 3 is low and that the rings are possibly to blame

3. The arcing sound tells me that one or possibly more of the coil packs is doing something it shouldn't

So after all this I gave the car a right caining, as it desrved no less, and everything was fine. Aside from the missing at idle, everything else seems in working order...

Plan of attack:

1. Talk to the tuner and possibly run it up on the dyno again to find out why it's running lean.

2. Get an endoscope and check out the damage to number 3 cylinder.

3. If not too bad - thrash the car like normal.

I'm thinking that the low compression has always been there and I'll fix it when I get round to doing a full rebuild..

Comments? Opions? Have I reached the completely wrong conclusion? Help is needed...

Cam

PS - if you got this far - thanks for taking the time to read it!! :D

Link to comment
https://www.sau.com.au/forums/topic/20986-blown-plugs-and-it-still-works/
Share on other sites

  • Replies 42
  • Created
  • Last Reply

Top Posters In This Topic

Nope.. I'm thinking that a bit of low compression in one cylinder is something I can live with for a while.. What I am worried about is why it is running lean when the fuel ratios were ok on the dyno...

Ever since I ran up more boost I've had a problem with the car misfiring. Its not all the time just now and then, pulling the plugs out and looking at them doesnt really show the car running too rich, although the dyno's AFR says different. I'm thinking my missing issue could be something simular to cams.

if you melted a spark plug end i would be checking the air fuel mix this tends to be a severe warning that you are running too lean,the next sign would be cooked rings resulting less compression and or a hole melted into the top of the piston,i have seen this happen before and it's easy to avoid.Check the fuel pump and pressure reg are still working correctly,if so ask tuner to recheck air fuel ratio are correct.Good luck and i hope this helps.

Thanks guys for the input so far..

Micko - yea - it ain't the injectors.. definitely coming from under the plastic cover.. quite loud..

GTS5000 - when i pulled the plugs today - all were white so something has leaned things out.. not sure why it would've changed from the settings on the dyno tho.. am going to get the ratios checked again asap...

It was still doing the stall thing when it tried to come down to idle.. Once the idle stabilises it seems to be ok..

oh yea - I'm not trying to blow it up, but a bit of low compression isn't a worry. What is a worry is the fact that it's running lean and the coil packs are arcing.

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

    • The rain is the best time to push to the edge of the grip limit. Water lubrication reduces the consumption of rubber without reducing the fun. I take pleasure in driving around the outside of numpties in Audis, WRXs, BRZs, etc, because they get all worried in the wet. They warm up faster than the engine oil does.
    • When they're dead cold, and in the wet, they're not very fun. RE003 are alright, they do harden very quickly and turn into literally $50 Pace tyres.
    • Yeah, I thought that Reedy's video was quite good because he compared old and new (as in, well used and quite new) AD09s, with what is generally considered to be the fast Yokohama in this category (ie, sporty road/track tyres) and a tyre that people might be able to use to extend the comparo out into the space of more expensive European tyres, being the Cup 2. No-one would ever agree that the Cup 2 is a poor tyre - many would suggest that it is close to the very top of the category. And, for them all to come out so close to each other, and for the cheaper tyre in the test to do so well against the others, in some cases being even faster, shows that (good, non-linglong) tyres are reaching a plateau in terms of how good they can get, and they're all sitting on that same plateau. Anyway, on the AD08R, AD09, RS4 that I've had on the car in recent years, I've never had a problem in the cold and wet. SA gets down to 0-10°C in winter. Not so often, but it was only 4°C when I got in the car this morning. Once the tyres are warm (ie, after about 2km), you can start to lay into them. I've never aquaplaned or suffered serious off-corner understeer or anything like that in the wet, that I would not have expected to happen with a more normal tyre. I had some RE003s, and they were shit in the dry, shit in the wet, shit everywhere. I would rate the RS4 and AD0x as being more trustworthy in the wet, once the rubber is warm. Bridgestone should be ashamed of the RE003.
    • This is why I gave the disclaimer about how I drive in the wet which I feel is pretty important. I have heard people think RS4's are horrible in the rain, but I have this feeling they must be driving (or attempting to drive) anywhere close to the grip limit. I legitimately drive at the speed limit/below speed the limit 100% of the time in the rain. More than happy to just commute along at 50kmh behind a train of cars in 5th gear etc. I do agree with you with regards to the temp and the 'quality' of the tyre Dose. Most UHP tyres aren't even up to temperature on the road anyway, even when going mad initial D canyon carving. It would be interesting to see a not-up-to-temp UHP tyre compared against a mere... normal...HP tyre at these temperatures. I don't think you're (or me in this case) is actually picking up grip with an RS4/AD09 on the road relative to something like a RE003 because the RS4/AD09 is not up to temp and the RE003 is closer to it's optimal operating window.
    • Either the bearing has been installed backwards OR the gearbox input shaft bearing is loosey goosey.   When in doubt, just put in a Samsonas in.
×
×
  • Create New...