Removing Stuck Exhaust Manifold Bolts

[Mississippi Winne]

I finally got my brakes in tip top shape and moved on to fixing an exhaust manifold leak.  I did plenty of research before tackling the job.  Recommended solutions were

(1) Clean the rust from around the edges of the bolt where it meets the manifold.  This allows penetrating oils like PB Blaster to work better. 

Bunk!  You will get little or no penetration around the head of the bolt.

(2)  Apply a good penetrating oil once a day for several days before attempting to remove the bolts. 

Bunk! The bolts are angled down.  Once I managed to get the bolts out there was absolutely no evidence of penetration.

(3) Use an impact wrench. 

This was an absolute necessity.  When I first started trying to get the bolts out I used a long breaker bar.  I put every thing I had into loosening a bolt and it didn't budge.  I went out and bought a good compressor and an impact wrench and went to town.  The first time I tried it I managed to get two bolts out.  This was going to be a piece of cake.  Not so.  The third one simply rounded off.  Went and bought a special socket for rounded off bolts.  The socket worked well and didn't slip, but my impact wrench just kept banging away doing nothing.  So I decided to boost the power by jacking up the air pressure to 120 psi.  Still nothing.  Went to Sears and bought the most powerful impact wrench they had.  Still just banged away and did nothing.  At this point I had cut emission stuff off the exhaust manifold so I couldn't even drive to a shop and get it fixed.  I ended up hiring a shade tree mechanic to come out and remove the heads so they could be taken to a machine shop to remove the bolts.

(4)  Apply heat to the bolt before loosening. 

The mechanic decided to give a go at removing the bolts before removing the heads.  After coming up against the same problems I had he decided to get a torch to heat the bolts.  Heat was the magic bullet.  The bolts need to be heated red hot.  It can be done with a good propane torch.  No need for a welding machine.  Also, whack the bolt one good time with a hammer once it is hot.  This helps break the rust seal.  An impact wrench is also a necessity.  The repeated hammering breaks the rust bond and is less likely to break the bolt than steady pressure with traditional wrenches.

In all, it ended up costing me about $1,000 to get those darned bolts out.  The good thing is I now have a compressor and an impact wrench, which I am sure will come in handy in the future.  The bolts were replaced with new stainless steel bolts so they won't be a problem in the future.  Now I can move on to getting the generator running.

Brian

[Mississippi Winne]

Before anyone suggest taking it to a shop first, I tried.  Midas said they would do it but just left the motorhome sitting for two weeks making up lame excuses for not fixing it.  So, I took it to the brake/muffler shop down the street.  They fixed the brakes but wouldn't do the exhaust manifold because the bolts looked like they had been in there too long.  Anyway, it is done but part of my maintenance checklist will be to loosen and re-torque the exhaust manifold bolts every few years to avoid this problem in the future.

Brian

[DaveVA78Chieftain]

On a Dodge 440 the bolt holes in the head for the exhaust manifold bolts are drilled into the water jackets.  When the bolts are removed, coolant will flow from the bolt hole.

For both Dodge 440 and GM 454:
When reassembling, use plenty of anti-lock compound (greatly reduces the rust/seizure  problem in the future)
The exhaust manifold bolts are only torqued to 20 Lbs.  Do not overtighten or the manifold will end up getting broken.

Dave

[LJ-TJ]

Brian, allow me to speak from experience to which I am sure several of the members will back me up on. There is nothing on these rigs that you, yes you yourself can't fix. It may look like a daunting task at first. But there is an endless amount of talent on this site that is more than willing to help coach you in a repair. Chances are unless you can make your way to "Wonder Brads a real honest to goodness Auto Mechanic  in Jersey" the mechanical work you have done will be worse that what you can do knowing nothing. Except the bill and believe me these so called mechanics have no trouble raping you when it comes to the bill. If it's broke you can fix it just ask. The stupidest question you have is the one you never asked.

[Mississippi Winne]

Thanks.  My biggest problem is a lack of time.  Working 50 hours a week at my day job and another 15 to 20 hours a week at my home based business leaves little time for working on the winnie.  I plan to do as much as I can but I was just stuck on this one.

Brian

[Mississippi Winne]

On a Dodge 440 the bolt holes in the head for the exhaust manifold bolts are drilled into the water jackets.  When the bolts are removed, coolant will flow from the bolt hole.

For both Dodge 440 and GM 454:
When reassembling, use plenty of anti-lock compound (greatly reduces the rust/seizure  problem in the future)
The exhaust manifold bolts are only torqued to 20 Lbs.  Do not overtighten or the manifold will end up getting broken.

Dave

The mechanic told me that my bolts had anti-lock lube on them but it had been on so long it hardened like glue.  He put a bit of motor oil on each one before replacing them.  That seems like a good idea as it is designed to withstand engine temperatures.

Luckily I have the stainless steel manifolds.  They have an accordion like section in the center to expand and contract.  According to the repair manual, stainless steel manifolds need to be torqued to 30 ft/lb.

Brian

[Mississippi Winne]

Update.  We got it put back together.  The exhaust manifold still leaked from the same spot.  Turns out that the previous owner let the problem go on so long it wore a groove in the exhaust manifold so it wont seal up.  Another problem I had was the 454 heads come in round and square ports.  The round ports are rare in a 1986 engine so I ordered the square ports.  Guess what.  Mine are round.  I thought that installing the correct gasket might fix the problem so I bought some beautiful copper gaskets and tried installing them myself.  Couldn't get one of the bolts in so I called the mechanic, and I use that term loosely but that is another story, to come out and put it back together well enough to drive it to the muffler shop.  I ordered some headers for a 70s Chevel.  No way I am paying $1,200 for Thorleys.  The next step is to limp my Winnie to the muffler shop and have them install the headers.  Hopefully that will fix the problem.

Brian

[Mississippi Winne]

Headers are on.  She is finally quiet.  The shop had to cut the motor mounts a bit for clearance and use a shorter oil filter but it worked.  No more thuga thuging down the road 8)  The headers were about $140 off eBay.  One step closer to camping.

Brian