The Dodge Challenger Message Board

Last week I heart a stupid noise under the hood of my 72 Challenger so yesterday I checked what it was. Well, it's the exhaust. It's leaking somewhere around the connection between the rusty (stock)exhaust manifold and the rest of my exhaust. I can't tell exactly where cause I can't see a damn thing in that area ! I know it's leaking somewhere there cause I can feel the air coming out of it at there.

How bad is this ? Can I just drive with it without wrecking some parts or is it important that I first repair it. But how can I repair it, anyone out there ever has this problem too ?

Drop the pipes, clean it all up, rebuild with assembly paste, fire it up,happy days, no problem!

Oh yeah, if it's the right side, check the heat riser thingy as well

Yeah, it is the right side. Where is the heatriser located Alex, after the exhaust manifold, cause somewhere there it is leaking. What is the function of that heat riser ? Can i just dump it if that's the problem ? But I think I bolt these manifolds off today and check the whole thing.

If you take the manifolds off the engine you may need to buy new gaskets. Also sometimes the mounting studs come out of the block. You will need to screw them back in tight using two nuts locked together on the stud. Use thread sealer as they go into the cooling system and will leak water without it.

There is a metal 'valve' in the end of the right side manifold. When new this would close when cold so that when starting the engine the exhaust (at idle) is re-directed back up through the right head, through a passage in the bottom of the intake manifold, and through the left head and out ito the left manifold and pipe. The pivot of the valve is offset so that when you rev the engine it pushes open.

This system heats the intake which is better for a cold engine.

As the engine warms the valve opens and gasses flow through the right pipe as normal.

The problem is that as the car ages the valve gets rusty and then sticks. Usually this is not a problem because it tends to stick in the open position. If it sticks closed or half open you are in trouble!

Most people cut them out.

I cut them out AND block off the passage through the intake so that it stays as cold as possible. This means it takes longer to get the engine going from cold but gives slightly more power when hot.

The gaskets have to be replaced when I bolt off the exhaust manifolds (they look already bad) so today I ordered a pair of new ones. These should arrive tomorrow so then I will bolt off the exhaust manifolds and see whats wrong. You said the valve is closed when cold...then I would believe the valve is stuck as it is closed because the previous owner hasn't drive the car since 1997 and I just driving with it since 2 months. So the valve might be rusted these years.

But if I understand it right it isn't bad when I remove the valve ? (if it isn't working as it should) Do I HAVE to block off the passage if I remove the valve ?? (What did you mean with when you REV the engine)

I will check everything tomorrow and see what's wrong. I'll let you know what's the problem.

Summit Racing sells E-Body headers for under $100.00.

Just remove the valve if it is stuck closed Hans. If it is stuck in the open position you can leave it alone or remove it. Your choice. Blocking off the intake passage is optional if you remove the valve.

Summit Racing are good but the racist bastards charge 'overseas' people $23 extra on each order.

Today I losen a couple of nuts so the exhaust manifold is almost removed. Good point about these gaskets, they were totally ruined. Glad I ordered a pair of new ones!

Between the exhaust and the exhaust manifolds, should there any gaskets cause I can't get the manifold of the rest of the exhaust. I bolted of the two nuts parallel to the exhaust but it's still stuck. I saw there was another nut at right angles to the manifolds, should I bolt these also off ? Also is there a way to check if the valve is stuck or not without removing the manifolds ?

And I keep it in my mind about these headers anonymous, if I ever need these it's not expansive... and thank you to Dave & Alex for the help so far. Ooh, I keep on enjoying this message board!!

Should just be the two nuts, there is a round gasket from memory, which is probably holding them together, give them a good shake and pull and they should come off

Don't know about the right angled nut, unless you are seeing the valve, Dave will know more about the set-up than me

It is such a long time since I saw a standard exhaust I am having trouble remembering!!

Yes two nut/bolts hold the pipe up to the manifold. There is a removable panel in the inner fender to help you get to it. I can't remember there ever being a gasket in mine. I think it is just sealed with exhaust cement. The valve flap is just inside the end of the manifold.

Today I checked why I can't get the pipe off the manifold and I probably know why...it looked liked it was welded together! So I couldn't get it off to check the valve. But it's probably open cause there comes equal smoke out of both exhausts when the engine runs at idle.

But I know now where the leak is, it's in the manifold just above/near one of the two bolts that hold up the exhaust. I started the car when cold and feel almost the whole manifold and I did feel the air at that place so I have to fix it but that's hard when it's welded together... I fixed the leaking of my power steering recently with some kneadable stuff that turns into steel in couple of minuts and that's still not leaking again so I think i gonna bring that onto the leak of the manifold too. Just see what it does. I don't have the time to get off the whole exhaust. Next winter maybe.

I don't think it will last long. The metal expands and contracts very much - breaking loose anything stuck to it. Plus the pressure from inside pushing it out.

Could it be that someone already removed the valve and the hole is where the valve mounted? This would have to be welded and may not have been done very well.

I dont think the pipes will be welded to the manifold, cast don't weld to mild steel well,I think they will just be tight or tacked with bad welding as Dave says, give them a good pull , they will come off !

"racist bastards charge 'overseas' people $23 extra on each order." This type of post is crap!!!

why is $23 to ship overseas unrealistic?

Hello Ted.
Nice to see you back here.

$23 is not bad if that was the shipping costs but this is an extra charge on top of everything else. It does not cost them any more to ship overseas. The customer pays all shipping charges and duties anyway. Other companies do not do it and in fact Summit never used to do it. The number of overseas customers they get has risen a lot lately and I think they are just cashing in on it.

Hello 'Me'.

What I said may be a bit harsh and probably over the top but at least I put my name to it. Please don't let this message board degenerate into the sort of thing we see on other sites where nameless people slag off other nameless people otherwise I will have to make registration to post here compulsory.

If you know why Summit and no other US company I have come across charge overseas customers extra please let me know and I will retract. It costs them no more to ship overseas than anywhere else as the customer pays all costs anyway. In fact I think they absorb the local shipping costs into the price so that many can get free shipping. Is that right?

I have made many purchases from Summit Racing (in the US) and shipping has always been free. They have always charged me a handling fee, $7 I think, but that was all. I had no idea they were charging my overseas peers an extra $23!

Shipping a medium sized parcel to, say, the UK by UPS costs about $100. Adding another $23 is like a slap in the face when you have already been kicked in the crotch. Don't need it!

Duty payable when it comes into the UK is calculated at 17.5% on the total amount i.e.

Cost of the parts + cost of shipping + $23 + Customs charges = Sub Total + 17.5%.

That extra $23 often makes just enough difference to make it not worth while on small orders.

It's ironic really. If like myself unless you were interested in this post you would not have looked in but seeing me's retort in the topics draws attention straightaway. What you said wasn't worded too well but 'me' didn't deal with it very well either.

Look for the loopholes Dave. If you have a connection overseas get them to make the purchase for you and then they ship the item dirctly to you, but...have them send it as a birthday gift = duty free!!! I did this a few times when receiving packages from England, the guy I dealt with attached a nice BD card, even wrote a personal note on the card to make it look legit. And presto, beat the taxman at his own game. (at least that's how it works here in Canada)

Summit quoted me $70 for shipping, charged me $120 ! Called them up and kicked off big time and they gave me the shipping at the original price, vat man still charged me on the big bill though, and it's not worth chasing them for a rebate, so I got stitched up, never dealing with them again

The leaking is gone. I finnaly got off the exhaust manifold so I could check it. There was a small 2mm hole in it so I went to the garage, they welded it. Had everything cleaned and installed again and there is no leaking anymore.

Thanks for all the input guys!

HELLO!
Listen....
To all my very good friends out there, (you know who you are) I don't know if you know, but last year instead of bringing back a nice shiney Duster from Florida, We invested in some property. We will be there for the whole of August this year, so if you need birthday presents sent, to you I could oblige. (only very dear freinds need apply) Not valid to the people that hate me.....

For extreemly good friends. I may bring them back as hand luggage..

I would take you up on that offer mate if I had any money left! I always spend so much over the winter that I am skint all summer!