Thread: Gav's 101.

With only weeks to go before I head north, I have run into a little problem...

The small exhaust leak on the back left hand bank is rapidly becoming a larger leak. I was going to leave it until I came back, but I don't think I'll be able to.

My question is to the brains trust out there - what will happen to the exhaust manifold if I -

(A) Try to tighten the bolts slightly.
(B ) Remove the manifold and replace the gaskets.

What I have found is that ALL the bolts are a little loose. They have locking tabs, but they aren't doing much. One bolt I was able to remove by hand, the others, once the locking tabs are just moved back a bit are all loose - that is with a socket on them, they don't need much to effort to shift them. I don't want to risk cracking the manifold this close to the trip, or I won't be going...

My original thought was to just nip them up and see how it goes, and if that shuts it up enough for now, leave it all until later, but I don't really want to risk it without some guidance...

Looks like all the bolts will come out easily if required, so no issues with seized bolts, etc.

I want to have a go tonight if possible, as I really only have a few evenings I can work on it between now and when I leave, as I have to go interstate next week, and won't be back until just a week before I head off.

hi baciat
could you use spring washers to take up some slack I did this once got me out of trouble hope this might help
your 101 looking better with all your work well done

cheers cooee

As tonight is 'get the engine ready and tune the bloody thing' night, I have been going over the rest of the engine. I think I may have worked put why it has been a bit off colour under full power - I went to check the timing and found the vac advance unit is shot, so a nice vacuum leak to deal with and no vac advance.

Now I just have to find a new one... It is a Bosch Scorcher electronic version, I'll pop over to ebay and see what I can find - anyone know a part number for these?

Oh, and it also needs new plugs and leads, but I have an almost new set of each from the old 3.5 I have sitting in the garage. I only replaced them a year before I ripped the engine out of the Rangie. Pity the dizzys are different...

Cheers - Gav.

Gav, if all the bolts are loose, that's the hard bit done! (They have a habit of welding themselves to the head then bringing their alli thread out with them!!) Do a bank at a time. Most of them can be reached from under the front arch. If you can salvage the lock tabs then great..... Mine has none.... Another thing that was left out. What it does have tho is a much thicker gasket that does two ports at a time. If you remove all but one bolt, with a bit of luck the original gaskets will fall out. From here you can slide the new ones in. Even if you take all the bolts out the exhaust does not go far, and there is enough flex in the pipe to pull the manifolds out and check/clean the faces. (I'm assuming both your manifolds are healthy and not cracked). Go for it I say! If I was nearer I'd come give you a hand!!

I also thought that the cracking issue was more to do with water hitting them as opposed to fitting and removal. Both the manifolds on my old 101 were cracked just behind the front outlet port.. It used to blow on each bank when cold then go quiet within 10 min so I never bothered with them until I removed the motor...

Garrycol once described 101 exhaust manifolds being made of glass.
It is a accurate assessment .
Yes throw the lock tabs.
It is not too hard to replace the manifold gaskets in situ providing the bolts/nuts will come loose.
If it is leaking, it will only get worse...........fix it.
After replacing a cracked LHS exhaust manifold on my 101 it performed a little bit better.

Bolts will come out easy - I have already stuck a socket on them all and checked, so I might give it a go. I'll grab some gaskets tomorrow. I am very lucky with this vehicle that is has extremely low KM and is in brilliant condition. It was never issued to a unit so sat in a RAF store for 20 years. From what we have been able to work out, it reached civilian service with VERY few KM on it. It now has 45,000KM, but has been meticulously maintained. It is only age that is catching things like this now. Every nut and bolt I have touched has come apart easily.

I also found a small exhaust leak on the RH flange where it joins the exhaust. This one I am not even going to contemplate until I get back, because I'm sure it I'll crack the manifold when I touch that one...

I'm going to have a crack (no pun intended) at making some new new manifolds when I have time. I have access to a fully equipped workshop which has everything I may need. I was over there tonight playing with his CNC plasma cutter. He has just upgraded it so it cuts 35mm mild steel with ease. Cutting some 12mm steel plate tonight was like a hot knife through butter.. Got to love that...

I know this has been covered by previous threads, but the quick search I did didn't turn up all the answers. Just trying to get everything straight in my head.

So, questions are-

What should the static timing be on the old 3.5? A sticker on the dizzy says 10 degrees. Yes/no?

Once that is set, what would you expect the mechanical advance (vac advance disconnected) take the timing to at say 4000rpm?

With the vac advance connected what should I expect to see at idle (with high vacuum) and if I can figure out how to take a reading, under load at wide open throttle (no vacuum).

Clear as mud?

I suppose most of this doesn't really matter as the engine has been going very well until recently, and at the moment I am assuming the dead and split open vac advance unit has caused the pre ignition I have only recently experienced?

All comments welcome.

Cheers.