New exhaust/engine? chugging sound - Need Advice please!

[Mara'sMagic]

Hi all,

On a road trip currently with my 85 westy and today it was feeling fine - pulled up at a campground to ask a question while idling, and when I started moving again the engine/exhaust sounded significantly louder - I would describe it as a puttering or chugging sound. Can hear it while idling and while driving in gear, seems more significant at lower rpms but I didn’t really go faster than 25mph after hearing this noise so I don’t know how it sounds in higher gear. We also smelled what we think was exhaust after this sound started. Fortunately we were at our campsite for the night so I didn’t have to put any more miles on it for the day. I plan to take a closer look at it in the morning and can definitely take a video to try to record the sound, but I’m looking for any advice on what to inspect and check for! Entering the weekend I know I can’t get in to a shop until Monday morning and want to make sure I’m not doing damage by continuing to drive until then. Many thanks!

Al

[VicVan]

Hi,

Possibly an exhaust leak. Usually happens at the seams between two sections of the exhausts. Engine off, get your head down there and inspect with a headlamp. I doubt you'll find anything.
Then turn the engine on, and try to pinpoint the noise location using your ears, and the back of your had to sense the flow of hot exhaust air. Watch out : it will heat up very quickly!
If you find a leak, a good temporary fix is exhaust repair paste. It's like a thick toothpaste that hardens under hot temperature.
Tell us what you find, good luck.
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'90 Little Blue Truck, 2WD auto, FAS GenV 2.0 NA (AVH)

[Wildthings]

The pipes will break at the elbows where they leave the heads. The metal on the outside of the pipe thins over time and eventually becomes physically weak until suddenly the pipe just breaks in two.

You can also have bolts loosen or break other where in the system leading to a sudden large leak.

[Blakesinclair]

I had (have) a pretty rough exhaust on my 85. The original bracket system was pretty crappy to begin with, so if the brackets weren’t broken yet, they might be now. Once loose or broken, bolts can loosen up at all the pipe junctions.

My poormans smoke test has been to check for leaks early in the morning when there’s still a lot of moisture in the system. Gonna be even better in a moist forest while camping. The steam will seep through any gaps or cracks more visibly than exhaust smoke. So I’d probably take a look around quickly once the car starts before it warms up.

Obviously do the cold inspection first though. Don’t wanna go rattling any hot exhaust pipes with your hands.
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1985 Weekender Vanagon 1.9L - Manual

[Igeo]

Hi fellow Oaklander!
Hope your campsite is working out.
With regard to the exhaust noise- If the engine is developing a miss related to fuel delivery or ignition, then you would probably experience similar symptoms. So the question: Is the engine running normally otherwise? If so, y'all are on the right track in focusing on the pipes and connections. If not, we'd need to dig deeper.
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1987 Westfalia 2.1 WBX Manual

[MarkWard]

I thick rag held over the exhaust pipe outlet should help pinpoint the leak. In theory, a sealed exhaust should stall the engine when the tailpipe is plugged. Hopefully it’s not a header pipe flange where it attaches to the head.
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[dobryan]

I run my hands near the exhaust pipes as soon as I start a cold engine and can easily feel the puffs of exhaust from a leak. But you need to be careful as the exhaust pipes near the engine heat up fast.
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Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

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[Mara'sMagic]

Definitely thinking it’s an exhaust leak - thanks for everyone’s insight! Going to try to find a muffler shop in the area, though probably can’t get in until Monday morning.

[Ahwahnee]

I once lost the bolts holding the exhaust 'Y' to the down pipes - made a distinctive (& loud) chugging racket.

It was a Sunday on the Navaho reservation - no hope of finding a hardware store open.

There was a 'No Camping' sign at a pull out on the South Rim of the Grand Canyon that was mounted with 6 bolts and nuts though it obviously only needed 2 to keep it from falling down.

[Mara'sMagic]

Unable to get in to a shop where I'm at and trying to decide if it's safe to continue exploring and going on back roads or if I'm playing a risky game with this engine noise. Here is a video of how it sounded on Saturday morning - it's been sitting for a couple of days and is a bit quieter this morning though still has similar qualities to the sound. Any thoughts?

Here is a youtube video of the sound, apologies if there's a better way to share this here.

https://youtu.be/kIoQTZj0-gc

[MarkWard]

Plenty of advice was given how to check for an exhaust leak. I’m assuming you aren’t interested in checking yourself.

There are safety reasons and drivability reasons not to drive a vehicle with an exhaust leak.

So, without a shop to look at your van, all that’s left is for you to do is to continue on and hope, or get out the van alert app and start heading towards a place that can inspect and repair your van. Either way, I predict a good story. Good luck.
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[Mara'sMagic]

Ok so I can actually feel where the exhaust is leaking and it seems like there might be a loose bolt at this joint? letting it cool down and then going to try to tighten it and see if that resolves the issue. Is it possible that that's all that is the problem or would the loose bolt be a symptom of a larger issue?

[Wildthings]

It looks like there may have been a washer under the lower bolt that broke in two and fell off. FWIW, I like to use SS washers in this location or a washer head (flange head) bolt. Some people prefer using studs over bolts here.

Whether you can get the old gasket to reseal well again is iffy.

[Mara'sMagic]

[Mara'sMagic]

I can try to get a better, illuminated picture if that's helpful

[danfromsyr]

you reallllllly should get it to a shop.

you have a chance it'll just remove and you can slip a washer in place and get it back together and tight

but

there's a LARGER chance that the bolt will snap, or the threads will be/have stripped. and will require a 'mechanic's touch' to remove and replace.

you 'should' replace the gasket there as well. since the exhaust has been whisping by it and likely damaged the surface of the gasket.


now would 75% of us here just tighten that and go about our business.. yeah
but 50% of those would quite possibly encounter a stripped/broken bolt
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[MarkWard]

If the bolt is actually loose, I don’t see a problem snugging it. I wouldn’t back it out, because you may not get it threaded back. That’s the cylinder head exhaust port, and you mess that up, you may end up having to remove the head, engine or both. It these types of situations I have slotted a new gasket and “swung” it into place. It requires both flange bolts to be loose.

This is a job that the more time you spend, the less time it will take. In the last year a member started down this path and ended up with replacement heads, when a skilled tech could deal with this regardless of how it might go off the rails.
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[Mara'sMagic]

Is it a bad idea to use exhaust repair paste right at that joint? I can feel the air coming out right at the seam of what I am pretty sure is the gasket

[Mara'sMagic]

I did try snugging the bolt though I didn't try too hard b/c it didn't seem like it wanted to go anywhere and I didn't want to risk snapping it.

[danfromsyr]

no to the paste... it's actually almost NEVER a good idea.. very limited in it's application locations. fire and soot and pressure comes out a leak in this location.. add in there's various metal layers with the gasket, shrouding tab, aluminum head and exhaust flange.

take it to a (competent) mechanic.
it's not really a vanagon specific issue. any mechanic worth their salt has and can deal with a exhaust fastener. a young/junior mechanic will be learning on your $dime.

but I would recommend taking it to the BUSLAB though they are likely booked for a week(s) out.
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