Knocking under boost?

[MCDGexx]

Ok I have a thread about this when I thought it was the fans but I think this will get it more of the attention it needs to get it fixed. Basically under boost it sounds like a fan or something is hitting or rubbing againest something, a small ticking or knocking sound, which while the psi raises it gets faster. I don't have an aftermarket boost gauge so I don't know what psi it starts at, but it starts on the 2nd line up outta the 4 on the stock boost gauge. The turbo has no shaft play that I can tell, and there is very little oil along the walls of the top of the intercooler, none in the bottom, and none in a puddle or anything like that. Happens in all gears, but only when the boost reaches that certain point.

 

[robs90tsi]

Oops, I really need to read the rest of posts before I do so, but anyway double check at least for ANY play whatsoever in your turbo compressor wheel. Also, hows your oil pump?? Has that been ruled out as a culprit?? It could be possible that your oil pump isnt puming a sufficient amount of oil to supply the motor when its under boost, hence the knock?? Hows your oil pressure??

 

[robs90tsi]

You know what, I just thought of this, do you have acess to a dyno??? A lift?? If so, pop the hood, set up your car on the dyno or lift (a lift would probably be better) and run your car to the point where you hear the noise, and have someone try and pinpoint the source of that noise, just an idea...........

 

[xveganxcowboyx]

Are you sure your car isn't actually knocking? I'm a bit confused by your posts, but that could be a serious issue.

First thing's first, buy a proper boost gauge!

 

[dragonov_elite]

it almost seems i have the same problem with my turbo but most people i have talked to about it say it sounds like a boost leak. the boost leak could be causing your turbo too spool up stop and start spooling up very quickly and this is causing majore havoc with your turbo barring. in which case it will damage your turbo really badley and if not takin care of in proper time could make things very difficult in the future for your motor. good luck with it and keep boostin'.

just my .02 cents

anyone if im wrong please point it out i dont want to send bad info

 

[Talon96]

you running a boost controller? if you are, get a AFTERMARKET boost gauge. the DSM boost gauges are known to be toys and are not to be trusted above stock boost levels. also, check the spring on your wastegate to see if you arent overboosting.

 

[megadeth0]

It sounds to me like your exhaust manifold to turbo housing gasket is blown. Have some one touch the gas while you put your hand near there. You should feel the air pumping out. Until you find out for sure, DON'T BOOST.

 

[iiiwildfireiii]

1. Get a boost gauge
2. Do a boot leak test
3. Check your spark plugs and wires
4. Get a logger of some type so we can see what your engine is doing
5. Post results

 

[MCDGexx]

I am not running a MBC, I have one but it is not installed, for the reason I don't have a gauge. I am not boosting it at all, as I don't want this to mess up my turbo. I'm going to put a fan or something in front of it tonight and see if I can get the turbo to suck air in neutral to try and pin point it. Or do the wheels need to be moving?

 

[MCDGexx]

Wheres a link on how to make and do a boost leak test?

 

[megadeth0]

Wheres a link on how to make and do a boost leak test?

http://www.vfaq.com/index-main.html
It's under "Intake".

 

[GOT EVO]

sounds like knock to me. Your timing could be advanced somehow causing it to knock or you just have really bad gas.

 

[MCDGexx]

Ok after seeing a picture of how the 1g Factory boost gauge is, if its anything like the factory 2g. The point it starts knocking is about 0-1 psi. So ANY boost what so ever, will make it knock. But i'll know for sure when my boost gauge gets here.

 

[MCDGexx]

Woot problem solved! Imaginary cookie to megadeath0 for the exhaust manifold - turbo gasket being blown! Now to the dealership tomorrow to buy a new one. Do I need to remove the entire manifold/turbo to replace the gasket?

 

[MrBoxx]

You'll have to unbolt the turbo from the manifold and slip the turbo down a little bit if it still has the stock turbo stud on it. Now would be a good time to change that out to a bolt, if you can. You can order the gasket and the bolt at a local dealership if you don't want to order from a vendor and wait for shipping.

I would advise hitting the bolts with a penetrating lubricant like PB Blaster or WD40 before trying to loosen the bolts. Also, use a fairly large breaker bar to loosen the bolts; they tend to be very hard to remove. Once removed, the only thing left is the stud. Remove the nut and the turbo should be able to drop down a bit. The exhaust and oil drain might support it up a bit, but you may have to take off the drain line and unhook a few exhaust hangers. It might drop down enough to get the gasket off, but you should take the stud off and replace it with a standard turbo bolt. Replace the gasket and bolt the turbo back up. Use a little anti-sieze on the turbo bolt threads; high temp is good, but regular will work fine too.

Someone feel free to correct me if I left anything out.

 

[MCDGexx]

Yah i'm going the dealership route, just easier and quicker, i'll get a higher quality gasket when I decide to put the EvoIII in. What do I need to ask for when I go to the dealership? An exhaust manifold to turbocharger gasket and a turbocharget bolt? How do I get rid of the stud? Oh and is it safe to drive the car if i'm not pushing it at all? I need to get to school in the morning.

 

[MrBoxx]

When you go to the dealership, you can tell them you need a turbo-to-manifold gasket and one turbo-to-manifold bolt and two cup washers that go between the bolt head and the manifold, dimples facing out. You'll see what I mean when you take the others off. To be absolutely sure of what parts get ordered, you can take in a diagram like the following, or have them pull it up on their computer so they can get the updated part numbers.

You must be logged in to view this image or video.

The reason I say to point to a picture of what you need is because I called in my parts order when I upgraded to a 14b and told the parts guy at the dealership I needed a turbo-manifold bolt and a turbo-manifold gasket. What I got instead were 4 manifold-head bolts and an O2 sensor housing-downpipe gasket. This delayed my turbo swap by quite a few days.

To get rid of the stud, you can just use a vise grip pliers to grab it tightly and unscrew it, I believe. Use a lot of penetrating lube and it SHOULD come out okay. It may even come out as you turn the nut on top of the manifold, depending on which is more tightly siezed to the stud; the nut or the turbine housing.

You can probably run the car as it is, as long as no pieces of the gasket are in danger of getting stuck in the turbine housing. It'll be just like a pre-turbo exhaust leak, in that case.

 

[MCDGexx]

What number are the bolt and the cup washers on the diagram?

 

[MrBoxx]

In red, 40-47. In black, the bolt is right next to number 22. Sorry about the quality of the pic. I'll see if I can fix it.

Edit: Okay, I cleared up the image a little more. But here's what I found in a VFAQ article regarding part numbers.
"Turbo/exh man bolts - If you just want to remove the exhaust manifold or turbine housing for porting or other work, you should definitely remove the Turbo-to-exhaust manifold stud (#41) and replace it with a bolt (#22). It is a good idea to replace this stud with a bolt, as it makes removal of either easier in the future. If you get the MD132933 washers, make sure to get 2 per bolt, 8 total, as they are the 2G style, and are cupped to put pressure on the bolt and keep it from loosening. Install the washers with the dot facing the manifold for the bottom one, and the dot facing the bolt head for the top one (the dots go on the "outside", so the washers make a slight oval shape that is compressed when you tighten the bolt)."

MD132656 Bolts (90) {I don't know what the 90 means}
MD132933 Washers

Part numbers may have changed, so double-check with the dealership.

 

[megadeth0]

I would not remove the stud. In fact, I use four studs on mine. The bolts tend to back out over time. I bet when you go to remove the bolts they will all be loose, hence the reason you blew out your gasket in the first place. Yes, it will make things easier for a swap but the studs are better all around in my opinion. If the bolts are not cooperatiing, some PB Blaster added with a little heat works wonders. You have two coolant lines front and back which are banjo bolts, get new copper crush washers for those. Unhook your oil lines and remove your AC fan. This should be enough clearance to remove the turbo. While it's off, get that thing ported. Good luck man!!

 

[MrBoxx]

The reason I mentioned removing the stud is because he said he's going to be putting in an EvoIII 16g at some point in the near future and I thought having the stud out would make extracting the turbo later a good idea. He shouldn't have to totally remove the whole turbo just to change the gasket; it should be able to slip between the manifold and the turbo flange if he can lower the turbo a little bit and take out the stud at the same time. The bolts shouldn't back out if you use the stock 2g cup washers and torque them to about 40-45 ft/lbs, then re-tighten them when the manifold and bolts are hot. This has worked for other people who have had the bolts loosen themselves.

He's also on the T25. Porting, while making for good experience, probably wouldn't be worth much, especially if he's going to upgrade to an Evo3 16g soon.

I'm pretty sure the stud and gasket can be replaced with the turbo still on the car, just dropped down a bit, which would make things a lot easier and less time-consuming, that's why I suggested that he try it without removing all the water lines and oil lines unless he absolutely has to.

 

[MCDGexx]

Ah well went and ordered the gasket, the bolt, the 2 washers, and a dipstick,(its broken), came out to 25 bucks, gotta go pick it up tomorrow.

 

[MCDGexx]

Ok got the stuff, and when I took out all four bolts on the turbo the gasket just slid right out, I can't find a stud anywhere? was it already removed or something? Also does the ridge on the inside of the gasket go up againest the manifold or the turbo?

 

[MrBoxx]

Someone must have already replaced the stud with the bolt before you owned it. Nice surprise. I don't believe it makes a difference which side of the gasket is up and which is down, but I may be wrong.

 

[MCDGexx]

Well got everything installed, and the car is running alot better, not only is the car not ticking, but it sounds better at idle, and just feels better all together