Check your intake manifold bolts

[HEMIMANN]

Ok guys, I've had some more run time on the truck since we re-torqued the intake manifold bolts.

It's not psychosomatic - the engine no longer sputters and misses on start up and at low idle. The intake manifold was leaking.

Holy crap. 6 years & 53,000 miles. I will check them next summer and see how they are. I guess if the engine starts sputtering again, I'll know.

Thanks to @Wild one per usual.

 

[Wild one]

Ok guys, I've had some more run time on the truck since we re-torqued the intake manifold bolts.

It's not psychosomatic - the engine no longer sputters and misses on start up and at low idle. The intake manifold was leaking.

Holy crap. 6 years & 53,000 miles. I will check them next summer and see how they are. I guess if the engine starts sputtering again, I'll know.

Thanks to @Wild one per usual.

I have a 5/16's or 8mm nutdriver in all my FCA vehicles,just for checking intake bolts,lol.I give them a check every oil change,if i can move them with a nut driver,it's time to re-torque them,lol

 

[HEMIMANN]

They're 8mm bolt heads.

It's ridiculous. I might have to get an engine creeper after all. The 2500 is tall, you have to climb into the engine bay. At 65 with arthritis, it ain't happenin'. My son crawled in their for me. I'm the tool handler now.

Maybe high temp Loctite will help. I doubt it, though if the manifold is just cheap, blow-molded plastic. It will keep squishing out from the bolt head. A big, hardened washer would help but can't really get one in there.

 

[Wild one]

They're 8mm bolt heads.

It's ridiculous. I might have to get an engine creeper after all. The 2500 is tall, you have to climb into the engine bay. At 65 with arthritis, it ain't happenin'. My son crawled in their for me. I'm the tool handler now.

Maybe high temp Loctite will help. I doubt it, though if the manifold is just cheap, blow-molded plastic. It will keep squishing out from the bolt head. A big, hardened washer would help but can't really get one in there.

8mm and 5/16's are basically cross-overs,same as 16mm and 5/8's

 

[HEMIMANN]

8mm = 0.31461 in

5/16 in = 0.3125 in

Engine is metric, so bolts are metric. No rounded bolt head corners here, boss. Now, what is the tool tolerance? Harbor Freight = +/- 0.25 in

I use either Craftsman (the previous Apex USA made) or Wright, who likely tolerance's to a gnat's a$$.

 

[mikeru]

I get what you're saying but you won't round off corners on a bolt that's torqued to that low of a setting.

 

[HEMIMANN]

Well, if torque is 90% of proof per Hoyle, the possibility exists, esp. if they're heat cycled in there. Most guys have metric sets these days in USA.

 

[mikeru]

Yup, most guys do have metric sets. I've got both. My metric tools are newer and kept in the large tool chest in my garage. Like @Wild one I keep one or two of the most commonly used tools in my older vehicles. I'm not dedicating one of my better tools for that so I go with whichever older metric or SAE tool will do the job. I've often used a 9/16" socket in place of a 14mm. I wouldn't torque them down to spec with it but it will do in a pinch. I've never rounded off a fastener because of doing this. You can't go wrong with using the correct size wrench/socket, but if I'm stuck somewhere with limited tools I won't hesitate to use it.

 

[Wild one]

8mm = 0.31461 in

5/16 in = 0.3125 in

Engine is metric, so bolts are metric. No rounded bolt head corners here, boss. Now, what is the tool tolerance? Harbor Freight = +/- 0.25 in

I use either Craftsman (the previous Apex USA made) or Wright, who likely tolerance's to a gnat's a$$.

2 thousands differance isn't going to round off a bolt head at 9 ft-lbs of torque,especially considering the 5/16's is the smaller of the 2 sockets lol. If a 5/16's fits it's actually the better socket to use

 

[HEMIMANN]

Boy, I've rounded enough bolt heads from crappy tools and frozen bolts to last a lifetime.

All maintenance work done inside our heated shop, too.

 

[Wild one]

Boy, I've rounded enough bolt heads from crappy tools and frozen bolts to last a lifetime.

All maintenance work done inside our heated shop, too.

I had an uncle who had the ability to tighten bolts till they squeaked,and would often break for the next guy who went to remove them,i remember my Dad threatening to punch him out a few times,after he had to work on something his older brother had his hands on ,lol

 

[HEMIMANN]

Before I could get some modulation into my eldests son's arms, he'd snapped off 4 bolt heads. I think they were 3/8, not structural, but still.

 

[HEMIMANN]

Here - you guys need these - https://www.wrighttool.com/innovation/wright-grip

 

[HEMIMANN]

The more I drive the Ram after tightening the intake manifold bolts, the more amazed I am.

I gotta hand it to @Wild one for alerting us to this. I can definitely confirm now that this eliminated idle stumbling. No longer any doubt the cause of start up and sitting idle stumbling was air leaking into the intake manifold past the seal. I drove the truck like this since buying it used in May 2018 with 13,000 miles on it (It's a 2017 Model built in Jan. 2017.) I thought it was normal, that they set lean idle for EPA (anyone remember Chrysler's Lean Burn 'system' from the late 1970's?)

Obviously, the MAP sensor at the throttle body set the AFR along with the TPS - so the excess air being sucked in through the leaky gasket cause it to run too lean @ idle rpm, and that's exactly how it behaved. At higher rpm and load, the amount of air ingested into the throttle body far outweighed that entering via the leaky gasket via reduced intake vacuum, so no noticeable stumble except @ idle rpm.

It makes obvious sense upon reflection, but I wouldn't have dreamed a crappy clamp design was the cause.

This ramble is for anybody wondering if it's worth it. If your engine is stumbling @ idle, the answer is 'yes'.

Thanks to @Wild one

 

[RedSRT4Me]

For those of us with 100,000 miles or more consider replacing the bolts. It is known that bolt threads stretch. So instead of doing this job repeatedly get new bolts, proper temp loctite, torqued in sequence and enjoy.

You might get as much 30hp back depending on how bad your situation is.

 

[HEMIMANN]

Yes, if they need repeated torquing. Wild One seems to imply they do, but at some point you'd think the plastic underneath would squish out to the point of no longer sealing. How many re tightens to that point?

Anyway the important thing is to go inspect. I doubt 30 hp gain from a seepage idle leak, tho. But it won't sputter at idle. Which is annoying.

 

[RedSRT4Me]

Yes, if they need repeated torquing. Wild One seems to imply they do, but at some point you'd think the plastic underneath would squish out to the point of no longer sealing. How many re tightens to that point?

Anyway the important thing is to go inspect. I doubt 30 hp gain from a seepage idle leak, tho. But it won't sputter at idle. Which is annoying.

The squish is not the intake manifold but the $12 per runner OEM gasket that is sealing the IM to the cylinder head. That is what would be squishing out.

You can doubt the 30hp because again it's a case by case basis but numbers don't lie

 

[mikeru]

The squish is not the intake manifold but the $12 per runner OEM gasket that is sealing the IM to the cylinder head. That is what would be squishing out.

You can doubt the 30hp because again it's a case by case basis but numbers don't lie

It's true that numbers don't lie but you didn't provide any numbers to back up your 30 hp claim. I have no idea if you could lose that much. I'd think the engine would stop running before you got a large enough leak to affect power that much. But until someone provides numbers for that it's all speculation.

 

[RedSRT4Me]

It's true that numbers don't lie but you didn't provide any numbers to back up your 30 hp claim. I have no idea if you could lose that much. I'd think the engine would stop running before you got a large enough leak to affect power that much. But until someone provides numbers for that it's all speculation.

I did the tests on my own vehicle. I gained that much back. I don't have my results anywhere handy. Giving you numbers from my experience with this.

And no you won't stop running you'll be chasing P219 codes forever till you figure out these bolts are tied to the problem.

That and you'll misfire at idle like you got bad gas

 

[HEMIMANN]

Anyone look into an improved aftermarket intake manifold gasket like the made for aluminum head gaskets to cast iron engine blocks?

Remember how those tore and leaked like a sieve due to vastly different thermal expansion rates of aluminum and cast iron? Dumping coolant into the engine oil? It took them a while, but they fixed it with steel backed elastomers of some kind. No longer a cheapo felt gasket.