2001 Bugeye possible detonation, ringland failure
 

Hi guys,

2001 bugeye, stock tune, only GFB non underdrive crank pulley.

so, had a mechanic have a look at my intake piping while he was fixing up an exhaust leak and rocker cover gasket leak. I suspected there may have been a leak but couldn't be bothered taking it off myself and didn't have the parts to fix/replace it and figured he may as well have a look when he was doing the rest. He found the hosing behind the intake was perishing, took some photos that showed oil was all caked up and leaking out. He sealed it up temporarily to see if that would help for now. Wrong gasket came for the dump pipe repair so that is being done soon. The car has been sluggish and he agreed, I was thinking the exhaust leak combined with a possible boost leak might be why

I take it for a drive, and it definitely pulls better now, builds and sustains the boost better. I still have a WEEEEEEEW whining sound, not sure if this is normal though, has been doing it since I got the car and have never driven one before. The thing that worries me now, is that I can hear what sounds to me (from watching other videos) like detonation. Its a raspy, rattly sound like a salt shaker or marbles. I get this at WOT around 3.5-5k. This is accompanied with what feels like a bit of hesitation. It's not dramatic, just a slight judder as it pulls.

The amount of oil in the intake is pretty concerning to me at this point. I have a catch can (that is picking up basically nothing), the car doesn't appear to be consuming oil judging by the dipstick. However, there must be some amount of blowby as it is collecting in the intake hosing.

I made a previous post about a tapping/knocking/slapping sound that received no replies. This issue still persists. Sometimes it goes away when warm, other times it gets worse, sometimes it is not there at all. I appears to come from the passenger side (australian car) when I'm driving the car, though is harder to pinpoint under the bonnet when I manually blip the throttle cable.

This has got me thinking, and I'm worried it may be the infamous cylinder 4 piston ringland failure. I figure this could account for the lack luster performance, excessive oil in the intake and now, with it boosting better, the possible detonation I am hearing.

After a hard drive, I popped the cap off the oil fill, and in the dark with a phone light, could see a light, wispy smoke rising. My heart sinks. After letting it sink in, I go for another drive, buy some different fuel and see if it still does it. Yep, still there. I have another look at the oil cap, this time I see no smoke. There is no smoke from the tail pipe either.

I'm deliberating on asking for a compression/leak down test, but I don't want to look like a paranoid idiot when there is no problem. I have heard mixed results on whether a small amount of smoke from the oil fill cap is ok/normal. Some say it 100% ringland issue, some say a little is ok. The fact I couldn't replicate it makes me think perhaps it was just condensation on a cold night, combined with the lighting, therefore I was able to see a very small amount of smoke. Combined with the other symptoms the car is exhibiting though, I figure it very well could be the piston/rings

Any advice, comments or anecdotes are much appreciated

edit: turbo has been removed and inspected, no issue there. Car also has a rather high idle when cold, ~1500, its a bit rough and then drops, almost feels like its stalling but not quite. Idles normally when warmed up

Might be worth logging to see whats going on

I don't have one atm. I was thinking about getting one, one day, to go with my eventual bits and pieces. But looking at the cost of a rebuild/engine swap, I'll never afford anything, ever again :P

What fuel are you using,octane rating?

I'm using BP ultimate which is 98, I think that is equivalent to 92/93 with the octane rating system in the US if that helps

this is rod knock and if you hear it your engines dead : hopefully its not that. air / vacuum leaks are always problematic on turbo cars and if your mechanic has patched up the intake thats never gonna work or last long. if its rod knock it wont matter much but if not get the intake sorted and any other leaks. high idle usually points to a leak. logging would show your air fuel ratio being off as well if you had access to a laptop and software.

The noise I hear, that is suspected was piston slap, sounds similar to how that one begins, but it doesn't persist through the rev range. It only happens when you blip the throttle lightly, slaps 1-4 times and stops. However, sometimes it does persist when you rev lightly and smoothly up to about 3-4k, I can only replicate this sometimes. I was hoping this might be related to the exhaust leak, or potentially lifters. Every catastrophic (and normal) noise video I hear all sounds like noises that I can hear, with many identical sounding things being attributed to all number of different conditions, some fine, some not. Its all a bit confusing to me. I don't have the ability to log anything atm, my nearest tuning garage would be over a 2 hour return trip, the next nearest being a 6 hour return trip, otherwise I would have gone straight to one of these places and got the whole lot sorted to begin with, plus a tune

rod knock is very specific, as in the video with a slow build up of revs it will start to knock and its a very specific sound too, a metallic type knock/ thump sound. i would start with the basics and fix the leaks. replace the intake pipe with a good 2nd hand one. matty the breaker on here sells them dirt cheap (20 quid or therabouts) mine was chewed up badly and letting air in at the turbo. replaced it and car purrs like a kitten and idles perfect.

I fully intend to sort everything out shortly, what I am more concerned with is the fact I am hearing what sounds like detonation and I'm worried about possible ringland failure

https://www.ebay.co.uk/itm/VAGCOM-US...sAAOSwMl9aeBeH
Laptop and Romraider, log what is "happening" and stop guessing.

I don't have a laptop but I guess I could get one of these if I ever have access to a laptop in the future. Will any of these scanners do?

And the shipping cost to Tasmania................:D

Same as here in the UK

This is not an issue, I can get some either from a wrecker's yard or 2nd hand from the mainland and sent via post. It wont be too bad.


On a slightly different note, still possibly related, I have another question
Say you lug the engine below 2000rpm. Not that I do this often or deliberately, but it has happened. Is it normal to hear a god-awful scrapping sound coming from below? I can't find any information about this, other than not to lug your engine. I'm just wondering if this indicative of anything

If I was you,I would either take it to a mechanic and leave it with them to find out what's wrong or I'd start taking things apart myself to see what I can see or do.
1st get that intake replaced as said before it isn't going to run right with a knackered intake.
then while you've got the intercooler off you can look for anything else.
if you can get the various gaskets for say the dump valve and throttle body then I would get these and change myself while your in there.
how handy with the spanners are you?

Also If you've taken the turbo off etc,did you use a new proper metal gasket when you put it back on?
again any kind of exhaust leak isn't going to help and can be noisy .

I'm not sure, my mechanic has been handling this as I wanted it to all get done together. What he did was have a look behind the inter cooler as i suspected a leak, found it and patched it temporarily. He checked the turbo and put it back, fixing the exhaust leak in a couple days. I assume he used the right bits and pieces. As for how handy I am, I'm a complete beginner. I have installed a catch can, crank pulley and (on another car) a custom air intake. I could get the inter cooler off and put the new pipe work in myself, no hassle. I'm limited with what I can do as far as tools go, I only have basic shed tools

I think my next thing to do is to take out the spark plugs for 2 and 4. I haven't done that before, but I watched a guy struggle to get them out once with those spark plug sockets. It looked tedious, but I have nothing else to do tomorrow

Plugs are easy with right socket.
make sure it's a thin socket as I used a fat one and got it stuck in the hole as the holes are tapered into where the socket sits.
think it's 3/8 drive you need.
the turbo gasket has a crush ring on it so if he 're used it it could be buggered.
then there is the uppipe to turbo gasket.
I would be checking these gaskets are sealed properly and all the bolts are in and tight,not spinning.
good luck.

I know this is old but did you get to the bottom of the cause of the possible detonation sound/ sound at low revs etc ?

It was his suspension after a trip to scoobyclinic :)