I was out for a drive two days ago and while fairly under hard (~3/4 throttle) in 2nd gear the engine started to sound like it blew an exhaust gasket.  I let off the throttle a little to ease the load on the engine and sound when away.  Under light load the engine sound normal.  I believe the noise is coming from the #3 cylinder/exhaust port. Everything else seems normal.

I thought it may a carb sync issue so I played around with the sync link, as it was off a little bit, but it did not make a real change.

I took a video so you can hear the sound, albeit somewhat muffled.

Any ideas?

I really appreciate any thoughts or ideas.

Thanks and I hope you all are staying healthy,

Chris

It's only Money, You'll make More!

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Original Post

I'd take the valve cover off on that side.  I'd check that push rods are operating correctly (aligned), that the rockers go up and down - with valves as you manually turn engine over.  Then I'd adjust the valves - that might show a broken/stretched valve stem - if one is way off. 

#3 exhaust used to be the one that went first on VW since the oil cooler blocked flow to it.  You want to catch a broken valve before it beats a hole in the piston and spreads shavings throughout your oil galleries and bearings.

Thanks Wolfgang!   I did pull off the valve cover and checked the valve clearance and the head bolts and all was good. 

I checked all the exhaust ports and all is good and tight.

I played some more with the carb linkage and idle and air adjustments to make sure they were in sync but not a lot changed.  

I worked a ton on VW engines in my high school and college days, but they were all had a single carburetor.  May be time to take it to some who know what they are doing😩.  

@Csquared

Chris, in light of all you mentioned, this may more than likely be an exhaust leak. Possibly from the area you originally suspected (#3).

Although the nuts on the exhaust port may seem tight, the gasket may be cracked or split. Only way to be certain is to remove exhaust and visibly check gaskets.

Hope you get this resolved without any major issue and back on the road! 

Last edited by MusbJim
Gordon Nichols posted:

^^^^^^That!

And if it isn’t a blown exhaust flange gasket, I would look for a cruded up idle jet on that side.

And if it isn't either of those two, I'd check for that typical intake gasket suck(intake gasket failure).

Well my day got a lot worse!  I had some tools under the hood and pulled out while working on the carbs.   I cleaned everything up and decided to go a drive to see if anything improved.  

About two miles into the drive, on a nice downhill on a two lane road, the hood flew up, hung there for a second and then flew off the car!   I never fully closed the hood and the safety catch did’t hold  the load at 50 miles an hour.  Luckily there was no other damage other the hood itself.  And more importantly no one was hurt by the flying hood!  

I plan to call Henry tomorrow to see if I can buy a new hood.  This is all bad timing as the weather is just getting perfect!  Not the best was to spend my Birthday😩😡🤬

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Csquared posted:

Well my day got a lot worse!  I had some tools under the hood and pulled out while working on the carbs.   I cleaned everything up and decided to go a drive to see if anything improved.  

About two miles into the drive, on a nice downhill on a two lane road, the hood flew up, hung there for a second and then flew off the car!   I never fully closed the hood and the safety catch did’t hold  the load at 50 miles an hour.  Luckily there was no other damage other the hood itself.  And more importantly no one was hurt by the flying hood!  

I plan to call Henry tomorrow to see if I can buy a new hood.  This is all bad timing as the weather is just getting perfect!  Not the best was to spend my Birthday😩😡🤬

Wow, you are lucky to have escaped with so little damage. Henry will get you fixed back up.  Maybe until then you could run as a superleggera?  Oh, and may your birthday proceed with better outcomes.

Sorry to hear about your hood.  A call to IM will help you. 

I forgot to latch mine once and the second one hung it to 50mph.  Wow, what a fright. 

 

It honestly doesn't look that beat up for flying thru the air.  The hinges can be rebonded in and any dings filled and repainted.  Your probably looking at $800 for replacement hood plus costly shipping. 

http://www.rustytubs.com/porsc...-car-front-h356.html has replacement hood that fit most kit cars.  Exterior is $395 and it has to be bonded to the interior substructure piece which is $150 --- so $545 plus shipping from NV with "some assembly required."

I have an extra front CMC trunk lid in OEM black gel coat.  It has one very small chip (dime size on edge (as I recall) and is drilled for the hood handle.  PM me if interested. I'm in NW FL (just 12 miles west of Destin).  It has been stored in garage all these years.

 

 

Last edited by WOLFGANG

Wolfgang, might have a point y0ou should look into it.  @Robert M  Now that is a great suggestion, to have an expert like Carey look at it.  I am sure they would do a bang up job fixing the hood up.  I mean you won't have to look at doing all the seams either which will reduce the work a lot. 

Last edited by IaM-Ray

I would strongly recommend that you stick with IM for a new hood if you go that route.  Different makers will use different molds to produce their hoods and doors and one from Special Edition or Rusty Tubs (if available) probably will not fit precisely and will need a similar amount of fiddling with to make it match your IM body.

You old hood could be brought back to life, but without seeing and measuring it and pre-fitting it on the car to see if it is warped, I can't comment on how much work it might take.  A decent autobody shop used to working on Corvettes, or a boat shop that works on fiberglass mods would be able to tell you if your old hood is re-useable.

I have seen one other car that had the hood pop up like that, but while it destroyed the windshield, the hood stayed attached (more or less).  It still needed a bunch of work to repair it, but it eventually came through OK.  Merklin's body shop friend bought the car, spiffed it up and re-sold it a few years back.

Wolfgang and Gordon, thanks for your ideas and suggestions.   Theron gave the same advice, that is to get the damaged hood fixed.   I will check with some local shops that have experienced with corvettes/fiberglass and if they think it can be fixed  

Thanks to all for your help!

Good summary of issues to consider there Gordon.  

I would tape up the sides and refit the hood to see what I have to do.

Good idea!  I will place the hood in the opening to make sure it is not warped.  My only concern is making sure the mounting bracket are positioned properly when bonded back in place.  I am hope they will seat back in the original position. 

It should be a fairly easy open the fibreglass and reset the Angle bracket within the hood using minimal, quick glue, and testing it for hinge operation... then bonding it permanently.  

Finishing the edge might be the easiest step after that to a good FGlass man. 

I would give it a shot.  You never know, it may look worse than it is, all the damage seems to be on the inside, do you even need a repaint? Most likely but we can't see from here. 

 All the best in your repair journey ... 

 

P.S.  

BTW, I would ask @Alan Merklin to have a look at it I know he not at your door but he is pretty close to you and he could put it back together for you I am sure and he has a painter for you as well if that is practical. 

 

Last edited by IaM-Ray

I enlarged the hood photos and surprisingly the damage is not too severe , it can be properly repaired. The metal that is bonded into the hood needs to be reset in place and is the most difficult thing to do, ( 3M Panel Bond adhesive is stronger than fiberglass )  but can be done as long as the repair shop have the car too.. All hoods needs to be fit to the actual car that being some taken off the outer edges to get the correct 3/16 gap and your hood already has that fit. IMHO I would take the car and hood to a local shop this way it will fit correctly when done. With the repair, paint etc . expect $650 to $900.  P' Msg. me if you have questions.

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