Snapped Exhaust Manifold

[Mick]

About a year ago i had a slight leak from the exhaust manifold where it had broken 2 nuts off, 1 on each end of the manifold, so i removed it and had the manifold sand blasted, painted and the face of it professionaly machined and i put all new studs in and a new gasket so i had done the lot. Anyways about 2 months ago it suddenly got loud under the hood so i figured i may need to tighten up the bolts thinking it was slightly leaking, anyways i removed everything i had to so i could get to it and when i removed the heat shield i nearly fainted, it had snapped clean in half......

All my hard work was for nothing.... i vaugly remember seeing i faint line on it and thinking it was a crack but after i gave it a bit of a sand it went away, then i thought stuff it this is going to take forever to clean properly so i took it to get sand blasted, i carnt remember where the line was so i dont know if it was where its snapped or not. Has anyone seen this before or had it happen to them

[t_revz]

My old workute did that after having to repeatedly go through a car wash on site.

Aftermarket Ecu? Wonder if its running lean/advanced on cruise...

[StevenCJR31]

that is bad! thats gotten VERY hot to do that

[t_revz]

Check timing marks on cam gears/crank line up too

[Moodles2]

I've seen another cracked stock exhaust manifold on here, but it looked like a casting failure

[t_revz]

I've done it when my timing went retarded. Knew it had a fault but before having a chance to look at it I went up a long hill with too much throttle and turbine blades let go, pulled manifold from head and cracked and toasted wiring harness. Costly exercise

[Mick]

thankyou everyone for your replies, is checking the timing marks on the cam gears and crank lineup something i can do myself without any special equipment?

and if so can someome direct me in how to do it or direct me to a tutorial or something

[Mick]

both ends of tge manifold were warped and snapped the studs and i had it machined but since it was so warped and then machined it made the bolt holes not line up properly so i had to geind the bolt holes out a little so i could get it on, and i carnt remember if i followed the correct pattern for tightening up the manifold, could these things have helped cause this?

It is a pretty big gap in the break

[Mick]

i do have an inductive timing light and i know i need to clip it on the white wire loop on the coil pack loom but i dont know what to do from there or what the timing is supposed to be set at

[Mick]

i have removed the broken exhaust manifold and im curious if the colour of my valves is right, i was expecting everything to be black or at least very dark, my o2 sensor was about the same colour as the valves you can see in these pics

[Mick]

anyone?

[89CAL]

I'd say with the amount of heat that has been in this part of the engine, the valves look pretty normal. Probably nothing to worry about as they dont look that bad

[t_revz]

Prob white from the heat it just copped

Buy a short/cheap spark plug lead and put it between coil to plug as it can be more accurate than loop wire

[jjman]

I've done it when my timing went retarded. Knew it had a fault but before having a chance to look at it I went up a long hill with too much throttle and turbine blades let go, pulled manifold from head and cracked and toasted wiring harness. Costly exercise

how retarded was it to do this?

also how hard a tune was it?

I just found out my car has spent the last month at 4 degrees retarded via the CAS. Didnt do anything adverse and only seemed a tiby bit down on response and power...

[t_revz]

how retarded was it to do this?

also how hard a tune was it?

I just found out my car has spent the last month at 4 degrees retarded via the CAS. Didnt do anything adverse and only seemed a tiby bit down on response and power...

My Cas bracket was broken and had twisted. It ran fine when cruising, but backfired under decel and was very low on power under accel.

Sometimes a minute after turning the car off it would backfire.

[jjman]

ahhh, yeah thats pretty retarded!

Mine only felt about 5-10% down on power n otherwise ran fine.

Sometimes a minute after turning the car off it would backfire.

and that my good man is Awe-wait for it-Some!!!!

have you seen the movie Uncle Buck? (now im showing my age...)

[t_revz]

ahhh, yeah thats pretty retarded!

Mine only felt about 5-10% down on power n otherwise ran fine.

I was closer to 50% down. Was booked in to get checked but it didn't make it. Surprisingly on the highway I still got the same economy.

[jjman]

dang, did you do any other damage to it?

glazed bores? fouled O2 sensor n plugs dead cat etc?

[t_revz]

Changed mani, turbo, all studs etc and Cas bracket and it ran. It was using oil already before that so not sure exactly but 5 broken ringlands and 1 melted crown but that might have been due to a previous fuel pump failure when it started using oil.

All good now but

[jjman]

dang.

Well you might know a bit more about this question iv had for a while then.

If you say just crack/break 1 piston ringland. Would you have noticable symptoms or is it possible that just 1 or 2 would go unnotived besides a slight variation in pistion compressions via a compression test?