So sorry to post again but as I’ve mentioned Im very new to Mazdas. I need to get the exhaust manifold Gasket changed as its very raspy and clearly blowing under the heat shield.
Is there only one metal gasket between the head and the manifold? Ive found one on mx5 parts but read a post that suggested there were two together?? I know there is one attaching to the downpipe.
again…apologies for more posts but I am determined to get this car upto my standard. Thanks.
Daniel.
The factory manifold to head gasket is a metal gasket, consisting of 2 stamped pieces sort of stuck together.
that makes sense! so its actually one item but two sections. Thanks for clearing that one up for me.
Daniel
It is quite unusual for the exhaust gasket to fail, rather more likely is a failure of the manifold itself. I’ve seen a couple where the point where the 4 pipes join together has failed.
I would certainly take the heat shield off and investigate further before replacing the gasket.
Wise words.
M-m
True, when I fitted a new ss manifold, I chucked the supplied gasket, and reused the original metal one. The original is stainless steel; its difficult to imagine how it would fail. The manifold burnt through though.
On the early MX5s, Mazda had a considerably difficult time with the weld Ralph described. Which would lead one to conclude that on all of the MX5s with the welded tubular manifold, this would remain a weak point (there were some Mk2s that had a cast manifold).
thanks guys. Im having an mx5 specialist sort the gasket out. They break lot’s of mx5’s so if they do notice this its highly likely they’ll have spare manifold. What sort effect would a hole have on the cars performance?
If the leak is small, then the only effect is the noise. You would definitely know if there was a leak bad enough to affect the performance.
Good luck with getting it sorted out.
Hello again, I managed to get the heat shield off today to confirm the leak and I am contemplating attempting to fit a new gasket to the manifold myself. The nuts seem in surprisingly good nick so should come off with a bit of brut force.
Will I be able to fit a gasket without removing the manifold from the downpipe?
Also apart from the new gasket itself do I need to use exhaust paste or anything or does the gasket go clean onto the head/manifold?
Any advice would be appreciated…
Dan
The downpipe is attached to the bellhousing via a bracket, which will limit how much movement you have. Visible here:
Theres only one bolt to loosen, but its a bit of a reach.
Don’t use any putty etc on the gasket; just make sure the surfaces are clean.
excellent, so with that bolt removed I should be able to move it to the side enough to get a nrew gasket in?
If you have a UK car, you might also have an egr tube that needs disconnecting.
oh? please explain in a little more detail…
UK cars have an Exhaust Gas Recirculation valve, with a fitting on the number 1 or 2 runner on the exhaust manifold. I’m not sure the EGR tube is all that flexible, so you may need to disconnect this (screw fitting). Imports don’t have one.
I’m intrerested in the photo of the four branch ,I am on my second one trying to fit it the first had misalligned holes where it fits to the head so that got sent back and the second from jperformance is similair - has any one else fitted one of these and did you have to relieve the fitting holes at all ,I’m waithing for anther to arrive and hope this one will be drilled correctly but I am aware that the holes may drilling out - is this normal ? apart from that the manifold looks well made
Ron
The manifold shown was a MX5parts/ IL Motorsport chinese effort. Fitted the studs like a glove. Though the welds needed attending to after 3 years.
Never use exhaust paste on a cylinder head, or anywhere pre-cat. If dried up lumps of paste fall back in to the head it can cause damage to engine internals and if they fall in to the cat it’ll cause errosion or blockages. The gasket should work fine on it’s own.
My car is a MK2 so dont know if is the same but it is a lot easier to disconnect the EGR tube from the other end (ie inlet manifold) just 2 10mm nuts as the tube is not flexible, much easier to get at at that end as well, just fitted ss manifold to mine and the only real issues were getting the old one off, main problem was the bracket as mentioned earlier which attaches to the bell housing which was a right ■■■■■ as the bolts are hard to get at (17mm) and had never been removed on mine before, lots of plusgas and grunting and a son who is a lot stronger than me helped but once off the new one went on fairley easy. In my opinion it was well worth the money as the car now feels a lot more responsive and smoother + no rattles ( which it had before).
Mikey