Anybody know what the heck this is?

EdGs · Sep 15, 2022

I wonder if the mds might play a role in the warping of the exhaust manifolds. You wouldn't think there would be enough temperature difference with 2 cylinders deactivated, but who knows.

Is manifold warpage/bolt breakage as common of an issue on non-mds engines?

Rlaf75 · Sep 15, 2022

Wild one said:
Manifold bolt and manifold breakage has been an issue for as long as i can remember.My dad had a side business back in the 60's/70's brazing up and repairing broken Ford manifolds

Yes manifolds breaking but not bolts popping off

Wild one · Sep 16, 2022

Rlaf75 said:
Yes manifolds breaking but not bolts popping off

Same basic principle breaks both the manifolds and the bolts,plus the bolts also carry the weight of the exhaust system. I still wonder if the trucks exhaust system is also a contributor to the back bolts being the ones that always break.The 5.7 cars use basically the same cast iron log manifolds as the trucks do,but they don't break the back bolts like the trucks do,which makes me think it's not just expansion/contraction and manifold warpage breaking the bolts,but it's also the weight of the exhaust system bolted to the manifolds.It's always the back bolts that break,if expansion/contraction /warpage were the issue,you'd think the middle bolts would be more inclined to be the ones to break

Rlaf75 · Sep 16, 2022

Wild one said:
Same basic principle breaks both the manifolds and the bolts,plus the bolts also carry the weight of the exhaust system. I still wonder if the trucks exhaust system is also a contributor to the back bolts being the ones that always break.The 5.7 cars use basically the same cast iron log manifolds as the trucks do,but they don't break the back bolts like the trucks do,which makes me think it's not just expansion/contraction and manifold warpage breaking the bolts,but it's also the weight of the exhaust system bolted to the manifolds.It's always the back bolts that break,if expansion/contraction /warpage were the issue,you'd think the middle bolts would be more inclined to be the ones to break

That's basically my point. You don't see this type of stuff on other vehicles.

Mittens · Sep 16, 2022

I think it's a good bet that my cars and family cars that I've worked on all had iron heads. Guessing it's less of an issue with similar metals... which is why I haven't heard of it.

Wild one · Sep 16, 2022

Rlaf75 said:
That's basically my point. You don't see this type of stuff on other vehicles.

GM's break manifold bolts and warp their manifolds too,they're as bad if not worse then the Rams 5.7

CheechDogg.0n37s · Sep 16, 2022

Wild one said:
GM's break manifold bolts and warp their manifolds too,they're as bad if not worse then the Rams 5.7

I was bout to say that lol ... the damn trucks at dish network that the quality inspection guys drove were GMCs and those things had broken manifold bolts all the time ...

Wild one · Sep 16, 2022

CheechDogg.0n37s said:
I was bout to say that lol ... the damn trucks at dish network that the quality inspection guys drove were GMCs and those things had broken manifold bolts all the time ...

The company runs strictly GM 3/4 and 1 tons,and there's always one in getting manifold bolts at least once a month. They also go through oil pumps alot more often then the Hemi's do,and the new GM's eat pushrods like they're going out of style.The local GM dealer stocks pushrods by the case these days,lol

Burn2k12Ram · Sep 16, 2022

Wild one said:
The company runs strictly GM 3/4 and 1 tons,and there's always one in getting manifold bolts at least once a month. They also go through oil pumps alot more often then the Hemi's do,and the new GM's eat pushrods like they're going out of style.The local GM dealer stocks pushrods by the case these days,lol

is why I find it funny when some say that Hemi's are trash with these problems and will be going to ford or gm next. I start thinking they must not of even read up at all about the others lol. They have just as many if not more issues.

Wild one · Sep 16, 2022

Burn2k12Ram said:
is why I find it funny when some say that Hemi's are trash with these problems and will be going to ford or gm next. I start thinking they must not of even read up at all about the others lol. They have just as many if not more issues.

The only good thing i'll say about Ford is they're still keeping their ICE engines around for awhile yet,lol

Mittens · Sep 16, 2022

Wild one said:
The only good thing i'll say about Ford is they're still keeping their ICE engines around for awhile yet,lol

That’s the only good thing? They’re soon to have the only 2door muscle car offering. Except for the vette, but that’s not the same class.

Rlaf75 · Sep 16, 2022

Wild one said:
GM's break manifold bolts and warp their manifolds too,they're as bad if not worse then the Rams 5.7

And if you actually read my very first comment I actually said ram and gm trucks

TomB 1269 · Sep 19, 2022

I like the idea of the exhaust system playing a part in the manifold bolts. I know most cars are transvers mount engines. Its been a long while since I've been under rear wheel drive car. However I believe most still use some flex joint or spring bolt at the exhaust to manifold or y-pipe to exhaust connection.
This may help explain some of the issue as there is no give in the system.
That and the thermals in a truck engine bay vs cars is much different, and I know that the aluminum vs cast iron heat transfer is much different and will put additional load on the manifold bolts. The truck bay may allow for faster head cooling, but more heat retention ate the rear of the exhaust manifold then the front resulting in a twisting/warping from the difference in cooling of manifold, both while in operation and when shutdown.
And then there is the just weaker flag on these newer manifolds to start.

Wild one · Sep 19, 2022

TomB 1269 said:
I like the idea of the exhaust system playing a part in the manifold bolts. I know most cars are transvers mount engines. Its been a long while since I've been under rear wheel drive car. However I believe most still use some flex joint or spring bolt at the exhaust to manifold or y-pipe to exhaust connection.
This may help explain some of the issue as there is no give in the system.
That and the thermals in a truck engine bay vs cars is much different, and I know that the aluminum vs cast iron heat transfer is much different and will put additional load on the manifold bolts. The truck bay may allow for faster head cooling, but more heat retention ate the rear of the exhaust manifold then the front resulting in a twisting/warping from the difference in cooling of manifold, both while in operation and when shutdown.
And then there is the just weaker flag on these newer manifolds to start.

The cars are dual exhaust with a cross over back by the mufflers,so they have less weight hanging off the back of the manifolds then the trucks single midpipe will hang on the back manifold bolts.The cars use the same basic manifolds and flange type set-up as the trucks do,no flex pipe or spring bolt on the cars either. The cars engine bays are alot tighter,so maybe the bay itself helps,but i wouldn't bet on it ,as the cars exhaust system will creak and groan way worse then the trucks system does when you shut them off.After a good hard run,you can hear the cars system groaning/creaking for upwards of 5 minutes on cool down,lol

njjeff201 · Sep 19, 2022

Rlaf75 said:
Yes manifolds breaking but not bolts popping off

I worked for Ford dealerhsips 17 years barely saw broken manifolds. Maybe 2.... MAYBE!

Rlaf75 · Sep 19, 2022

njjeff201 said:
I worked for Ford dealerhsips 17 years barely saw broken manifolds. Maybe 2.... MAYBE!

Ok

18CrewDually · Oct 24, 2022

5.4 3V Fords eat passenger side manifolds. They rust between the manifold and stainless layered gasket and pop the rear studs then leak exhaust. It is called rust jacking. I just did one on a 2009 last week and requires atleast unbolting the passenger side mount and jacking the motor up. Ford by the book says to remove the engine.
You can see the layers of scale that popped the studs broken clean off at the rear cylinder. The corrosion also took out the starter by again jacking the starter breaking the flange and bending the other 2 bolts. East coast winters are a killer. I've seen popped rear fasteners on all 3 manufacturers.

joesstripclub · Oct 25, 2022

Wild one said:
The cars are dual exhaust with a cross over back by the mufflers,so they have less weight hanging off the back of the manifolds then the trucks single midpipe will hang on the back manifold bolts.The cars use the same basic manifolds and flange type set-up as the trucks do,no flex pipe or spring bolt on the cars either. The cars engine bays are alot tighter,so maybe the bay itself helps,but i wouldn't bet on it ,as the cars exhaust system will creak and groan way worse then the trucks system does when you shut them off.After a good hard run,you can hear the cars system groaning/creaking for upwards of 5 minutes on cool down,lol

I wonder if the cars also have stiffer motor/trans mounts. That would put a little less stress into the exhaust system.

Wild one · Oct 25, 2022

joesstripclub said:
I wonder if the cars also have stiffer motor/trans mounts. That would put a little less stress into the exhaust system.

They use very similiar motor mounts,the way they bolt to the frame is differant,but other then that they're virtually the same

Andrei20 · Nov 1, 2022

And that's why on some exhaust manifolds some manufacturers use spacers, to have a really (you would wonder why so long?) long stud that will have the variation of tension in the fastener due to heat expansion distributed more evenly and be less affected by the heat expansion of the manifold itself. It's an engineering trick, we studied that in the university (mechanical engineering in automotives). Some manufacturers use those spacers, some don't and save a penny per stud.

demonram said:
Exhaust manifolds made from cast iron, attached to an aluminum head results in broken manifold bolts. The difference in cooling time is more than the manifolds and bolts can take after so many heating and cooling cycles.

Anybody know what the heck this is?

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