Anyone had exhaust manifold issues?

IndyAndy · March 30, 2019

2014, 5.3L V8, 67,xxx miles

Recently, my truck has developed a squealing sound when accelerating when it is cold. It goes away after a few miles, but you will hear it a little still even after warmup. It will also have an obnoxious squealing at startup from cold, usually for about 15-20 seconds. I took a video of the startup and sent it to my buddy who used to be a mechanic and he said it sounds like an exhaust manifold. After taking a closer look, there is black on the exhaust manifold on the passenger side furthest side to the firewall. Also, at startup, I am getting exhaust fumes inside the truck.

I'm assuming this is covered under the powertrain warranty? Also, has anyone else experienced this/heard of this happening?

Hillwood · March 30, 2019

Any broken bolts?

1SLOW1500 · March 30, 2019

Where is this leak? At the donut gasket or the head?

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Snowcamo · March 30, 2019

43 minutes ago, IndyAndy said:

2014, 5.3L V8, 67,xxx miles

Recently, my truck has developed a squealing sound when accelerating when it is cold. It goes away after a few miles, but you will hear it a little still even after warmup. It will also have an obnoxious squealing at startup from cold, usually for about 15-20 seconds. I took a video of the startup and sent it to my buddy who used to be a mechanic and he said it sounds like an exhaust manifold. After taking a closer look, there is black on the exhaust manifold on the passenger side furthest side to the firewall. Also, at startup, I am getting exhaust fumes inside the truck.

I'm assuming this is covered under the powertrain warranty? Also, has anyone else experienced this/heard of this happening?

Sounds like leaking manifold gaskets. Do you have an aftermarket exhuast? Might be loose exhuast hangers causing the manifold to shift/ move in turn wreaking the gasket.

mikedeezxxx · March 30, 2019

Chevy is known for broken exhaust manifold bolts. It’s usually the rear passenger or rear driver side bolts. Most likely your problem.

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IndyAndy · March 30, 2019

20 minutes ago, 1SLOW1500 said:

Where is this leak? At the donut gasket or the head?

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The head.

IndyAndy · March 30, 2019

3 minutes ago, mikedeezxxx said:

Chevy is known for broken exhaust manifold bolts. It’s usually the rear passenger or rear driver side bolts. Most likely your problem.

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My mechanic buddy said the same thing.

LH Lead Foot · March 30, 2019

The factory exhaust manifolds are cast from a high silicon alloy, but still iron and can be welded. The front or rear bolt is subject to snap off, due to lot of expansion and contraction with the engines temperature cycles, but mounted to an aluminum cylinder head, the expansion rate is still 2X aluminum to 1X the iron exhaust manifold.

The best fix is, if the bolt is broke, (Sorry) but elongate the bolt hole at the ends and use a stainless steel flat washer to allow some sliding while properly torqued.

If your lucky, the bolt will stick out enough to get vise grips in it, or weld a nut on it. But is below flush, use a center punch and an angle drill to get a straight hole drilled into it. I able, drill all of the way through it if you feel comfortable that it's going straight. Use another exhaust bolt to gauge the length of depth to know when to stop, but the drill will "Drop-In" if you go all of the way thru. I believe this relieves stress in the bolt, but most come out easy. Plus, you can spray a penetrating oil into the hole and let soak...While you contemplate the task with a beer in one hand and wait to let the liquid work.

"Warning; This maybe a two or three beer job at this point." Use Zip 45 penetrating pray oil, but everyone has their favorites.

"The easy-out" Most have aggressive reverse coarse flutes to aid in grabbing the broken bolt. I like the brand "Ridgid" sold in different sets, even on SnapOn trucks, but they use guides, a fluted extractor tool of the correct size and have a match nut, that slides over it up close to the piece. Using a hand ratchet and deep 6-point socket works best as you can feel the movement or resistance.

I have a habit of using a good anti-seize compound like Permatex Anti-Seize lubricant 80078 I think is 8 oz. with cap mounted brush. I have 6 or 8 or these. Since the late 60's working on motorcycles and imports with aluminum to iron parts, I have found invaluable.

I have seen the bolts break on the ends, but not the middle. So the expansion theory makes more sense to me. I will us it every time on my own vehicles.

Not related, but use dielectric grease on connectors, bulbs, flashlights and even smoke detectors. Everything electrical especially on really & fuses in under-hood electrical centers. (Note: Sold for cheap in home improvement stores with an automotive departments / don't forget "Marine Dealers, as they have large tubes cheaper by the ounce.)

The OEM exhaust gasket is a multi-layer steel type. Aftermarket replacements and many sold with headers, use a graphite type. I don't use these types, only the OEM types. Get the original gasket and put eyeballs on the holes location while on the head. Don't forget to check the depth once removed with a wire or whatever you can use, just to make sure it's clean all of the way in.

For diagnostics, short of having a mechanic's mechanical or electronic stethoscope, use a length of heater hose to the ear. A 4 or 5 foot length of 3/4" is all you need. Have a buddy start it for you if it only makes noise cold. Just place the hose near the suspected location first, then have your hand end / ear ready. You will be amazed how well it amplifies the sound, but this helps you figure out where the noise is coming from.

A good light and a swivel mirror on a stick, will allow you to see the black power if exhaust is leaking to help locate while cold.

Best of luck. Hope this helps.

Edited March 30, 2019 by LH Lead Foot
spell check sucks with mechanical words.

IndyAndy · March 30, 2019

I am still within 5 years/100,000 miles. Would this be covered under the power train warranty?

SteveCZ · March 31, 2019

17 hours ago, IndyAndy said:

I am still within 5 years/100,000 miles. Would this be covered under the power train warranty?

You can try..... I ended up having a shop replace all my bolts with studs and nuts, while he was in there changing the plugs and wires. Ended up having three bolts broken. Never had a smell or noise, so I was lucky, no warping of the manifold. Once you remove the wheel well liner, and tire, it’s pretty easy access to everything. Good luck!

Lsgun1 · March 31, 2019

On 3/30/2019 at 3:24 PM, IndyAndy said:

I am still within 5 years/100,000 miles. Would this be covered under the power train warranty?

Powertrain typically covers anything touched by an oil, so it probably won't be covered if that is the cause.

IndyAndy · April 1, 2019

https://www.valleychevy.com/chevrolet-powertrain-warranty/

"Seals, gaskets and manifolds"

According to this, I think this is covered. Hopefully, I don't have to haggle with my local dealer too much. My past experiences they don't really like warranty work.

LH Lead Foot · April 1, 2019

If you have no check engine light, the PCM may not capture any "Rich" condition as it only occurs cold while in open loop. A lean condition has to bad enough and exist for a given number of seconds under certain conditions, spelled out on the diagnostic flow chart for a code as;

Enable Criteria. (The conditions it takes to run a code check, no other certain codes, or the test is aborted and actions taken by the PCM is the condition is detected plus the type of code. A or B.

The dealer will type in the VIN number and check. Some have 5/100k power train but emission is a different coverage.

NOTE: if you are close or "Yes" on emissions for a leaking exhaust manifold and the service advisor says, no...then ask for "Service Manger". The case can be requested to be reviewed by the GM regional service manager who visits each dealer once a month if the service manager agrees. They will submit a request and face to face meeting, set a date, but be prepared to bring in all service records from outside the dealer.

Now, a leaking exhaust manifold makes noise, but if air is allowed into the up-stream exhaust before "Bank 1 / O2 sensor #1...this can cause a rich condition. This will show up on a scan tool in block-learn for that side. Have it checked out for this info to "See" if this can be used as "Evidence". If true dual exhaust, the effected side will be a little blackened. Injectors on that side, will show longer open time to fix a lean condition. For example, good side shows the injectors open at 0.8ms warm at idle, but bad side the injectors are at 1.2ms. The O2 sensor will show higher voltage. No existing O2 sensor codes, either current or history. (TECH2 might be the only scan tool that will show up to 5 history data captures W /all engine PIDs. Do not clear codes as this erases everything that would help your case.

If you do your own service, go to rock auto, eBay or where ever you bought actual replacements parts, get printout or screen capture for show and tell. Now, even though this does not have anything to do with your broken bolt / leaking exhaust or cranked manifold, it still helps to have documents. You don't want to show up at the dealer with an external fuel filter covered in rust with OE markings. Even top tier fuel receipts, clean vehicle, good tire with even wear, oil condition, anything that shows neglect. This shows the regional service manager that you "Do" try to take care of the vehicle. They will ask if your fuel economy has dropped since the exhaust leak started and request documents like fuel receipts or your mileage note book. Yes, some people do that. I had a customer who flew a private jet for a corporation and took notes, photos and wrote down answer I gave him for questions he asked. Glad he moved!

Search internet for same year, model, engine and problem. Take a screen shop or use a camera that shows 20 or 30 of this problem. Even on forums like this one.

Any TSB that indicates broken / leaking exhaust manifolds for "X" vehicle thru "X" year range.

(NOTES)

TSB's are for techs to use to resolve a customers complaint, by using a new repair procedure, parts, bolts, manifold or even elongating holes. A "Re-Call" is a monitory fix and must be checked by VIN with the service advisor checking while typing repair order just for an oil change. If not done, the dealer will not get paid for any other warranty item on the ticket. A RECALL is either open or closed. It will show up at the dealer by VIN, regardless if your 2,000 miles from home.

If a RECALL is not fixed, while other warranty is done, the dealer has to present a signed document by the customer, showing that you where in a hurry, had to be a the doctors office soon, or in a parade in 12 minutes...etc.

Now, this is important, if the meeting is not in your favor, ask for split. Many times, the regional service manager will cover parts, but you pay labor...even thought its not 50/50. But ask for equal split, it doesn't hurt.

Many people quit and do not go that far. But, be prepared for thorough inspection of the actual problem, notes about aftermarket parts known to cause problems will be taken and be on the Techs' ticket. If you have a "Cold Air Intake", make sure the cotton air filter is not real oily as this effects the Mass Airflow Sensor.

(Last Step)

I was never a FORD dealer tech, but worked on enough to know I did not like them, but I was asked and become a stand-in FORD panel judge in cases where the owners felt the next step was a law suit and this was mediation by an impartial panel of Master Techs, Dealership Techs and others with motor vehicle industry ties. I don't know if they still do it, but it is an additional step in a process to keep a customer happy but keep out bad press.

A Local TV station may take it as a human interest story including their own go-to-car-guy. You know the one they go to when winter starts, they put him on a short TV segment to discuss low tire air pressure and wiper blades. A local dealer does not like bad press on the evening news.

(Just make sure the exhaust manifold is within the manufactures coverage before jumping)

Basically you have a number of common sense choices to follow. But remember, even a small claims court would require you to have a current ASE Master Tech stand next to you and speak, with all of the knowledge after he or she has put eyeballs on the problem completely. Photos, receipts mean a lot, but not parts. Do not attempt to bring used auto parts into court.

Lets say that over a decade ago, I have been the voice of official experienced car guy, a number of times, but only once in small claims court. But, W/O an ASE Master in small claims court to give positive testimony for you, you will loose every time.

Hope it works out for you.

IndyAndy · April 4, 2019

Truck is at the dealer. They are saying exhaust manifold gasket. Not sure if it is just a gasket failure or a broken bolt.

Covered under the powertrain warranty.

cardo · November 24, 2019

CI have (3) sheared off bolts on the DEF exhaust system within the last 2 weeks. The truck is 2011 2500 Silverado. These bolts are broken off inside the hole, can they be tapped out or need to be drilled?

Phil