Stage 2 Troubleshooting Thread - My pain = Your gain!

[SlightlyEvil]

I hit many roadbumps and spent a lot more time and $ then I should have along the way to a smooth running Stage 2 LGT.

 

I just wanted to share a few of the problems I encountered that were quite simple but didn't seem to have any topics/threads with solid answers yet regarding on the forum. I know some of it is covered elsewhere but it was always a hassle to search for it since it was so scattered. I hope someone out there can find this useful. Please feel free to add to this with your own experiences if you find it helpful.

 

Disclaimer: Obviously I'm not an expert at this, and you're taking your own car's health, and sometimes your life, into your own hands by working on it yourself. A lot of the time its worth getting someone else to do this work for you, especially if you don't feel safe doing it yourself for ANY reason.

 

When Upgrading to Stage 2 form you'll probably experience some of the following:

 

FINDING LEAKS:

Leaks were a huge pain in the ass to find. They're caused by a lot of things I learned, but thankfully they leave tell-tale traces. If you want to you can feel around the various joints for leaks while the engine is running. To do this it's best to let the car cool completely, start it, and let it idle. You have about 1 - 2 mins before the exhaust parts get hot enough to burn you. You can also try spraying a mix of soap/water around a suspected leak area - if it's leaking it'll bubble up. A less effective method I tried but couldn't get to work for me was blowing cig smoke around a suspected leak, I suppose this would work in a perfectly still environment with a lot of smoke, but it was sorta a pain for me. Additionally if you just take a look at the gasket or the area surrounding the gasket you'll see a lot of exhaust soot which will wipe off. If you see this soot outside the flange, you've got a leak! Hooray!

 

WIERD NOISES:

(Quite hard to explain/diagnose on a forum!) It should be noted that when you install an aftermarket up-pipe and down-pipe you will hear a noticeable increase in noise from the turbo. This sound though will be there throughout the boost range, and will sound like rushing air that accompanies the turbo whine. This *isn't* a leak.

 

Problem Noise #1 - A loud high pitched tea-kettle whistle, only when the car is under substantial boost and only when it's in gear (can't be replicated when the car is parked in neutral by simply revving). Performance won't seem to be affected and you will still probably make the full amount of boost. From the driver's seat the sound was apparently coming from the area behind the glove box. This is a leak most likely involving the up-pipe, or the manifold elements (cross pipe, manifold). It seems to me the biggest problem area to look out for is the flange linking the bottom of the up-pipe to the manifold. The reason for the problem here seems to be that it's a 2-bolt flange, a poor choice. Since the turbo is often under tension already, and since the stock manifold/headers are made out of very tough cast iron, the up-pipe has to take up the majority of the flex. The top of the up-pipe where it mates to the turbo has multiple studs which means it is a much more robust connection, while the other end with its 2-bolt flange will clearly take the brunt of any flex and suffer leak very readily.

 

Solution: The best solution is to use an up-pipe with a flex joint. I had to replace my solid GT-Spec up-pipe with a flex one since my turbo seemed to be quite out of alignment range with it. Yours may not be, but mine was pretty bad. Despite the debate in various threads about flex vs. solid, I would without hesitation suggest you save yourself a huge potential headache and just get a flexible up-pipe. Additionally, using copper gasket/RTV/Permatex Ultra Copper on both sides of the gasket at 2-bolt flange will provide a much much better seal and eliminate any further risk of a potential leak forming. There's a reason the OEM up-pipe has a flex joint in it after all...

 

 

Problem Noise #2 - A loud deep rumble coming from around the turbo, when ANY throttle is applied to the car, in gear or not. I feared I had wrecked my turbo in some way after installing my flexible up-pipe! I was driving along and heard a ka-thunk (a bolt coming lose from somewhere) and from then on any throttle at all made the engine shudder and rumble deeply. It idled rough but did not vary in revs.

 

Solution: I spent a long time trying to find the lose bolt when this happened, since all of the other bolts on ALL flanges were still there and tightened down well. It turned out that the bolt that goes into the bung (threaded hole) on the up-pipe for the O2 sensor had worked its way loose and fallen out on the highway. This obviously introduces a lot of turbulence into the airflow!! There is a bung for the EGT on the manifold, but the up-pipe will also have one usually placed right below the flange that mates to the turbo. Make sure you put some high-temp loc-tite on this bolt as it might back off if you don't, and its located in a place that makes it difficult to access without removing the whole up-pipe! A washer isn't a bad idea, I made one out of some brass and it hasn't moved since.

 

Problem Noise #3 - A low quiet whistle from the exhaust that sounds a lot like an old air-cooled Volkswagen Beetle engine, when revving the engine at low RPMs (when pulling away or when the engine is revving down/shutting down. This is probably going to be a simple leak at one of the primary flanges in the exhaust system you're using. I had one where the left muffler mated to the Y-pipe as I was using the supplied Megan Racing gaskets with the dimpled surface.

 

Solution: The exhaust seems great but these gaskets suck. A bit of copper RTV helped seal this up though. I also tried loosening the mid-pipe/downpipe flange to try replicate this sound and found it was possible, so check this joint as well. These bolts can back off as well, so hi-temp loc-tite isn't a bad idea if yours start to leak after a few runs.

 

 

GASKETS:

There's plenty of threads about the various gaskets available for the various applications on the exhaust/intake on our car. Some people seem to love the Crucial copper gaskets, but I can't say I have experience with them. I ordered a remflex gasket for my up-pipe/manifold leak at one point but it didn't want to fit as the gap was too small and the gasket was destroyed during my clumsy attempt at installing it - your mileage may vary with these thicker-than-normal gaskets. I don't pretend to know anywhere near as much as these other threads, but I can echo them in saying that nearly every leak problem I had with my set up was related to using non-OEM gaskets at that certain joint. Aside from the donut gasket at the dp/mid pipe connection, I would use OEM gaskets everywhere. If its a 2-bolt flange, I've also made it my policy to use a bit of copper silicone/RTV on both sides of the gasket to make a good seal.

 

 

BRANDS - MIXING & MATCHING:

I initially installed the following setup:

GT-Spec catless up-pipe

Invidia downpipe with high-flow cat

Megan Racing Cat back exhaust system.

 

I had to do this out of circumstance and due to availability of parts at the time. It goes without saying that by mixing and matching parts from different after market suppliers you drastically increase the likelihood of parts not mating up perfectly. There were problems with everything I purchased, with the exception of the MR CBE. This was nobody's fault but my own, but a vital lesson to learn! Whatever brand you choose, it's best to keep it the same from front to back if possible! (I couldn't get a MR Catted DP, so don't flame me for getting the Invidia.)

 

*Special note, the Invidia Catted DP has one stupid unpublished 'feature' - it angles up severely back towards the drivetrain putting the flex joint in the mid-pipe of your exhaust under considerable tension and causing it to whack the underside of the bracket protecting the driveshaft during a hard shfit. I have had to get mine cut off and a new end piece put back on so it doesn't angle up any more.

 

I was NOT in doing this stuff before I started and I'm still a huge noob at it all, but thanks to a lot of people, namely PhilT and BoostJunkie (Paul) I had my questions answered as problems arose, and Phil was elbow deep in my car on more than one occasion helping me find leaks etc.

[DoubleM]

thanks for this. When I go stage 2 next spring, I'm sure thus thread will help me a lot. I hear problem noise #3 when my car is a little cold, but right now my car is stock.

[VTGT]

There are a lot of new sounds associated with stage 2. I heard a lot of sucking noises that seem to be in the dashboard area. Normal

 

The turbo likes to whistle with a up and dp

[SlightlyEvil]

Very good point, the turbo definitely makes a new whoosh or rushing air sound, but it's quite different from the high pitched squeal/whistle that a leak will make down there. Also, the normal added turbo sounds are there throughout the turbo's boost range but my leak was only audible at the peak of boost, so there'd be a whoosh first, then a squeeeeeeeal!

[tommypenguin]

Real good write up you have here, definitely will help others prepare correctly when going to stage 2.

[chenc544]

Good write up.

 

FINDING LEAKS:

Leaks were a huge pain in the ass to find. They're caused by a lot of things I learned, but thankfully they leave tell-tale traces. If you want to you can feel around the various joints for leaks while the engine is running. To do this it's best to let the car cool completely, start it, and let it idle. You have about 1 - 2 mins before the exhaust parts get hot enough to burn you. Additionally if you just take a look at the gasket or the area surrounding the gasket you'll see a lot of exhaust soot which will wipe off. If you see this soot outside the flange, you've got a leak! Hooray!

 

Another good way to find leaks is to spray some soapy water at the suspected flange. It will foam up really quickly right where it's leaking.

 

nearly every leak problem I had with my set up was related to using non-OEM gaskets at that certain joint

 

The only caveat I would like to add here is that sometimes the fitment is off enough that the thick non-OEM gasket actually helps. The OEM gasket are high quality but very thin so if the fitment isn't good enough they will actually be the source of the leak. The one leak I found recently was of this variety.