I just had Strup headers installed by a shop, they swore pretty badly about the installation, took them some 5-6 hours.

The problem is that once they had everything in place its leaking somwhere from the left header...

Either the gasket or welds... They even removed the header and re-fitted it again with the same result... Its clearly heard especially at low RPM's under load, but its pretty much impossible to feel/see any leak during closer inspection.

They re-used the stock gasket but the car only has 45k miles on it and they said the gasket was in perfect condition, and like i said they removed and re-fitted the header carefully inspecting the gasket a second time...

Does anyone have any experience of this problem or have any bright ideas of how to proceed here?

Thanks for any help

/Roger

 

When i installed the strup headers on my Z... i've changed the gaskets...and i had no iusses....

 

a. Not advisable. Its a crushable gasket with raised ridges around each exhaust port. Two thin pieces of metal with some sort of thermal insulation material between. After use, the raised ridges are no longer raised. The condition of the thermal insulation material? I haven't the faintest.


b. The surface of the header where it mates with the engine block is not flat? Its pretty simple to check the mounting surface with a straight edge before installation. Headers are not machined to high tolerances. And a new gasket will take care of minor imperfections. But if the surface is misshaped, it will not seal.

 

+1, get new gaskets and try again.

 

My header was distinctly un-flat and I levelled it before installation just to be sure I wouldnt have any problems.

Mike

 

what kind of noise are you getting?

 

Thanks for the help and thoughts guys. Even the instructions with the headers said that the stock gasket can be re-used if it looks in good condition... But i also think that is the most likely reason for the problem... It must be a really small imperfection since the guys inspected it twise and said it looks fine.

The header gasket is damn expensive here in Sweden, its ~60 USD per side so ill most likely have a new one (or two just in case) shipped to me from the states, does anyone know where i can order gaskets from? (i know performance nissan has them but their site is down...)

I havent listened to it myself yet (picking up the car within an hour) but they say it sounds almost like valve ticking, sharp and short bangs. Sounds to me like header leakage and most likely from only one cylinder.

Do you think there is any chance that it will settle in if its driven really hot?

/Roger

 

Just call performance nissan, you can still order parts over the phone I believe.

 

Go to the Ebay store of performance nissan... and send an email....
or you can order the gaskets from courtesyparts.com...

 

Thanks for the help guys!

I got the car back and have taken it for a test ride, the sound from the header leakage is quite significant and is almost as loud as the exhaust note itself... You can hear its only from the left side and from 1 or max 2 cylinders judging by the frequency. On top of this the HKS exhaust was apparently not fitting well at all, they had to heat and bend the piping by atleast 1" on each side, its still on occasion making contact with the diff or swaybar which is both audioble and feelable so they need to get back to work on that as well...

Ill proceed like this:
1. Order 2 new gaskets today (performance nissan or courtesy)
2. Have the shop take the header off and check if extremly carefully for any un-even surfaces etc
3. If possible to preasure check for any air holes in the welds etc
4. Install header with new gasket

That should cover any and all causes for a leakage

The HKS exhaust sounds amazing though, just to bad its all distorted by the leakage...

/Roger

 

Thanks for the heads up on the HKS, this is like the fourth time I have heard of this problem with contact with the differential. I was ready to buy, but I will wait till they resolve this or get the Espelier.

 

i wouldn't re=use gaskets w/ 45k on them.....

 

Sorry my bad, did the conversion between km and miles the wrong way, the car has less then 9k miles on it

At the moment the car sounds like a mix between a Ferrari (HKS exhaust) and lawnmowner (leaking header)

/Roger

 

have you contact STRUP directly yet? I think i have a leak too but too busy to bring back to check.

 

oh yea, then they should be good. I installed my headers/hfcs/etc... at 15,000KMs and re-used the cats gaskets (headers came w/ new ones though)

 

Every gasket, except the header to head gasket, is fairly easy to change. Use new header gaskets but try to reuse the original cat/header and cat/exhaust gaskets. If they leak it only takes a few minutes to change them out. Removing the headers to change the gasket is a different story!!!

I had a leak on the header/cat gasket on the passenger side. It was minor but I could see the black exhaust mark where it was leaking so I changed it.

 

No i havent, i want to make sure where the leak is first, first step would be to try with a new gasket and while having it removed inspecting the welds and surface very carefully.

/Roger

 

Yeah i know, ideally it would be the cat gasket but the sound is so sharp i am pretty sure its leaking between the head and header... Another couple of hours dissembly / assembly...

/Roger