Hi guys. I think my car has a vacuum leak. The other day I was merging onto the freeway and felt an extreme lack of power. Shortly after I got the restricted performance light and check engine light. I was also getting a little more surging than normal/mildly erratic idle behavior.

When I popped the hood today, I could almost hear a sucking sound from what sounded like the tops side of the supercharger but below the cast intake tube. Anyone have any suggestions?

The gaskets from the discharge of the blower to the charge coolers were changed less than a year ago and seem to be in good shape. It sounds like it's around there though.

thanks!

 

Check behind supercharger on drivers side for a grey with black line vacuume line that can be "blown off" under full boost.

 

check! That's a good suggestion but it looks okay. I'm letting the engine cool down a bit more and then I'm going to dig into it a little. I think it might be the gasket on the outlet of the supercharger. I mean the one that goes from the blower to the metal piece that splits the charge to the charge coolers. I couldn't visually see anything yet but I'll keep looking....

 

Fun... the gasket between the supercharger outlet and the metal piece that goes to the charge cooler is shot. The passanger side rear appears to be blown out. Part of the gasket appears to be hanging out about 1/4 to 1/2".

Anyone know if this gasket is available anywhere other than jag?

 

Well...that settles that. At least yer not diggin for nuttin.... Send the blower for a port/polish whilst swapping gaskets.

 

Sorry to hear that bro.... But by any chance can you Post up sOme pics of the area you are describing to visually see hOw it lOoks like? Thanks.

 

Here's a picture of what I can see. It looks like the gasket is pushed out a bit causing the leak.

My blower is already ported so I'll just do the bare minimum to get this fixed. The mods on my car are done. I'm just trying to keep the car running and get rid of the damn suspension squeaks!!

 

Okay, so I just went to the local jag dealer and the part is $82 after tax! Anyone know if there are any other places to get this that are cheaper? The discharge on the cobras and lightnings are different, so this may be a jag specific part (or possibly if toyota or someone else uses this blower).

It appears that the shop that did my hose under the blower re-used the gaskets. So far I've had two failures due to this. Now I know why they reused them; they cost a fortune.

 

Mine were replaced but gaskets were purchased from Jag. Stiegmier sells them too.

 

that's who ported my blower so I'll give him a call....

 

Have you sprayed starter fluid/propane around the gasket to verify they are leaking? Mine look pretty much the same and I have no leaks on my 2005 STR.
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qwiketz, tbird makes good sense to test the alleged leaking gaskets.

 

That is a good question. I do have starter fluid from an old project. So I should just spray it around the gasket and see if it gets sucked in and if there is a change in idle speed? it's been 5 or 6 years since I used it on a car that was having trouble getting started due to fuel system issues.

Are there any other potential vacuum leak sources near the middle top of the engine? I can definately hear something. Also, the restricted performance and check engine lights came on very shortly after the car wouldn't accellerate getting onto the freeway. It felt like and econobox when I was trying to merge.

I'm leaving on a trip tomorrow morning, so unfortunately, the diagnosis will probably have to wait until next week....

 

How about using a stethoscope. Good alternate method for reachable areas.

Good Luck.

 

Yes. Spray the gasket and surrounding area. Some people prefer to use propane. I would at least try it. If you can hear the leak over the engine it must be pretty large??
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I haven't seen what the gasket looks like, but if you want to save some money you can use OJ containers to make a gasket. Get the paper one with wax covering. I have used that in the past on high psi turbo cars without issue. Use an xacto knife to trace out the old gasket.

 

A large diameter rubber hose is a very handy device to behave as a stethescope. A generous length of it can be more easily manuevered than a stethescope. I employ this technique on some of my patients. The wiseguys speak into the other end. Just kidding, never used a rubber hose on em. But not kidding about using it to listen for motor noises and vaccume leaks.

 

There's some great ideas here. I do have a stethoscope from an old halloween costume so I'll try that method as well. I'll also try to spray a little starter fluid around the suspected area.

One of my coworkers said to see if I can buy gasket material and then just trace the existing gasket similar to what you said. Anyone know if gasket material is readily available at the auto part store?

I just got back in from a trip last night so I'll probably take a look at this after work.

 

I think you are talking about gasket # NCC7735BA. Which is #5 in the diagram? I think Jaguar of Greenville had it for $45?

 

awesome! $45 is definately better than $82, even after shipping.

When thecar is started, you can clearly see the gasket move inward about a 1/4". When the car is free rev'd you can see it push outward slightly in the area that is damaged.

I did use the stethascope and it worked. I could more clearly hear the sucking sound from the vacuum leak. It had a different sound than general engine noise.

Well, I'm going to order parts tomorrow and hopefully get working on it this weekend. The repair is a little bit of pain, but it's not nearly as bad as removing the supercharger. I'll have to remove the inlet tube, undo the intercoolers from the y metal piece(part 1 in the diagram above) and I'll have to remove the bypass tube off the supercharger. I don't recall if I need to remove much more, but hopefully not!

I'll try to post some pics while thework is underway.