• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Noises for your analysis please!

Share this page

If you spend more than an hour changing the exhaust manifold gasket.....sigh.

Easy job, remove heater hose bypass, after draining a bit of water from the radiator.

Remove fuel line at carbs.

Remove 5 manifold bolts, tilt both manifolds away from engine together, reasemble is reverse, lol.
 
jlaird said:
If you spend more than an hour changing the exhaust manifold gasket.....sigh.

Easy job, .
Click to expand...

Jack, it's a bit harder on the 1500. I use the open end of a 9/16 almost straight on the nut with a screwdriver through the other box end for leverage.

Did you use a 4 ex port gasket? If so, I'll bet it failed at the bottom of 2 and three. When you use a 4 hole on a stock ex manifold on the 1500, the center divider b/w 2 and 3 is exposed to exhaust gases on the back side and shrinks. There is no mating surface on the mainfold to protect it. As it shrinks, it pulls up the bottom portion of the gasket on the lower part of the two ex ports and creates a leak. You can use the 4 port gasket, just cut the center divider b/w 2 and 3 out. In other works, make it just like the ports on the ex manifold.( which only has three exhast ports. The factory gasket only has three ports)

My money says that's it. ( mine wasn't that loud though)
 
Wow, I'm impressed, Kellysguy. Would never have thought of that in a million years.

This is a photo of the gasket that came out when I re-done the head gasket a month or so ago. I replaced it with one exactly the same but have not yet done the disassembly.

I think you can see the leaks - and this one was not even making any noise.

Photos are front, back and where I cut out the center piece to see if that is what you mean.

ManifoldGasket.jpg


Cheers!

PS. What is your take on the bolt that holds the two manifolds together - when should it be put in - before or after the manifolds are bolted to the head?
 
Adrian, if you want a "new" exhaust gasket, I have both the type you removed and the type you made by cutting out the middle section. The "top" type is considered the heavy-duty gasket and it is generally used where headers are installed. The bottom configuration is the factory type used with the cast exhaust manifold.

The sounds do seem to be coming from the bottom end, not up high like the valves. Still, I would try all the top end, easily accessible stuff first. Even though you have adjusted the valves until you are sick of them, you may want to loosen them off and trying to slide them to the side a bit to inspect the rocker shaft. The TR rocker gear is nastier than the A-series parts. It is not unusual for the TR rocker shafts to become very deeply scored and allow a bit of extra rocker arm motion... probably with noises.

BTW, I hope that garage is warm and heated. Nothing is happening with my cars at the moment with our snow.
 
Doug,

I've a new gasket coming from Moss Motors and was just going to cut out that section with a Dremel cutoff wheel. Then I'll put that in and see what happens to the noise.

Yeah, we must have had 6-7 inches of snow - I'm not going anywhere!

I think you are right about the noise coming from down below - I'm begining to think the manifold gasket has blown on the lower part - as Kellys guy says - also it sounds like a leak noise rather than mechanical, but hey, what do I know.

Cheers!
PS. You know what I'm tempted to do - clean up that gasket and install it and see what happens. Or should I bide my time and wait for the new one to arrive?
 
Though you are not supposed to use sealant to an intake/exhaust gasket... a bead of Permatex-2B and refitting the old gasket may (temporarily) correct any gapping problems you are having. While only temporary it would give you an indication if you are correct about the source of the leak.
 
Back
Top