Pulled the plugs today and the front 2 were nice tan color but the 2 rears were carboned up and much darker. Any reason why there would be a difference between cylinders?
Possibly a manifold leak on 1 and 2? To get it to run right, you have to richen the mixture which makes 3-4 run too rich. Just speculation.....
Heat pipe? Yes or no.
Hal nailed it, there is obviously a big vacuum leak on the front manifold hole. A heat pipe won't fix it, that would just slow the car down.
yah i would think vac leak, try a new gasket set, buy the copper ring and gland set, they seem to work best.
heat pipe wouldnt effect 2 cylinders only. it would effect all the cylinders.
On most Ts I've seen the front plug is most sooty if all is well. Sure sounds like a broken down intake seal at the front hole.
Thanks, that makes sense. Yes it does have a heat pipe, but I think i'll pull the manifolds and replace all the gaskets. I sprayed the studs with some PB Blaster, hoping they will come off easy. Is stud breakage normally a problem? Just curious.
I just repaired a couple blocks with broken manifold studs. Na, never happens.
It does happen, not too often if you work on them carefully. Usually, one end or the other will unscrew just fine (an advantage to studs. Bolts, more likely to break). A little oil helps. If they don't come apart easily, the usual tricks apply, heat in the right place, soaking in penetrating oil, etc.
Be gentle, and good luck!
Drive carefully, and enjoy, W2
If you do decide to get the original type glands/copper rings gasket set don't be surprised if the ports don't line up.......
If there is a one or two piece composition gasket on the car now there is reason for it.......and it's probably not good.......says me.......buyer of two new exhaust manifolds........money well spent I might add.
One thing you would want to check is to make sure your intake manifold is straight and flat. I have run across a number of these that aren’t, although they look good. You can true them up with a large flat file, or have them milled. Same holds true for the exhaust manifold if you are using an original. If you are using the manifold ring and gland set up, you want to check and make sure you don’t have to take material off the gland ring after you have trued up your manifolds to make sure you have a proper seal. After this is all done, you can also use mega copper high temp silicone gasket sealer. This is recommended for exhaust manifolds. If you can’t find it locally, it is available at Langs. This will help seal minor imperfections in the block.