Blown exhaust manifold

[Alex197UK]

So my exhaust manifold has completely blown now, sounds like a tractor with no exhaust
I’ve decided after looking through a few threads to buy the toyo sport pre cat delete manifold.
now I’ve seen people mention about having to upgrade the engine mounts to stop the knocking on the subframe and to also make the flexi last longer, so the question really, is which engine mounts will need upgrading ie top and bottom or both, would appreciate some recommendations if they do need replacing.
Thanks lads!

 

[bedoef]

It isnt so much an upgrade as replace with fresh ones. The upper and lower engine mounts can go 2-4 years or so before they collapse enough for the manifold to touch the subframe. I elected to get powerflex inserts and they have done the trick so far, but that increases vibrations in the car.

That said, these newer batches from Toyo seem to go in without any issue or needing to notch the subframe.

 

[Alex197UK]

So the best thing for the car would be to get fresh engine mounts aswell as the power flex upper torque arm and the lower engine bushes?

 

[turkie172]

Basically the engine mount rubbers weaken allowing the engine to move around more and as the engine moves more the Flexi joints get worked more and since they are exposed to a lot of heat through time they get brittle and can split along with corrosion normally its the passenger side flexi that goes first as its further away from the center line of the car and as the engine moves it is worked more than the other. Also as the car gets work done on the exhaust system and engine/gearbox people pull and haul at them and don't realize how much force they put on the flexi's. People complain about the after market manifolds touching the subframe but by slacking the lower under the engine dog bone and the upper torque mount the engine can be rotated forward or back which allows the subframe clearance of the manifold to be increased and decreased some people were cutting lumps out of the curve of the subframe instead of doing this. So there is no point replacing the flexis without fixing the real problem that killed them and because they get nosier very slowly you don't notice them going off another place to check is cracking where the manifold is bolted to the engine you should be able to see soot around the welds a torch and a mirror make the job easier some people fit induction kits to distract potential buyers from the sound of the leaking exhausts and with the flexis leaking the O2 sensors cause poor fuel economy and bad running.

 

[bedoef]

So the best thing for the car would be to get fresh engine mounts aswell as the power flex upper torque arm and the lower engine bushes?

Well, if the car is a DD and you run the AC often, getting the PF inserts will drive you a bit mad. The torque arm and fresh upper and lower engine mounts should go a long way to ensuring the new manifold locates okay and you dont have any issues. Down the line, especially if you want to track the car frequently, the PF inserts are a good way to go.

 

[Alex197UK]

Cheers lads appreciate the knowledge as always!