Rebuilding the 4.3GL in my 1998 Sunbird 200SL

[Jprevat]

Ok so I was going through my Mahle gasket set and instead of the normal Multi layer exhaust manifold gaskets im used to I have a stamped metal set. Is there any prep or caution I should take with these? This may very well be an amateur question but I honestly cant even find a direct answer online.

 

[Jprevat]

This is what I have right now.

 

[Jprevat]

ok so thats not working

Here is the direct address but it wont let me add the actual link.

https://shop.advanceautoparts.com/p...23250mah/11647528-P?searchTerm=exhaust+gasket

 

[Bondo]

Ayuh,.... Those are good ones, no special treatment necessary,...

 

[Lou C]

I finally have some pictures. So yall dont think im building a ghost boat.

Looks real familiar, except mine doesn't have the balance shaft. Pre-Vortec and roller cam. I'm doing a top end overhaul this summer. Re-man heads and new exhaust. Keeping the old pre-vortec manifold because it's in good shape.

 

[Jprevat]

Ayuh,.... Those are good ones, no special treatment necessary,...

Awesome! I was a little worried since I hadn't seen those before.

 

[Jprevat]

Looks real familiar, except mine doesn't have the balance shaft. Pre-Vortec and roller cam. I'm doing a top end overhaul this summer. Re-man heads and new exhaust. Keeping the old pre-vortec manifold because it's in good shape.

That does sound pretty familiar. Lol

If it isn't broken don't fix it. You wouldn't happen to know what the pre-vortec 4.3s were rated power wise do you?

 

[Lou C]

My old heads had cracks in the center cyl exhaust valve seats. Old intake manifold is OK. AFAIK, the 2bbl pre vortec was rated at 175 and the 4bbl pre vortec was rated at 205. Mine has a Q-Jet...

 

[Bondo]

You wouldn't happen to know what the pre-vortec 4.3s were rated power wise do you?

Ayuh,.... 'bout 185 hp with a 2bbl. carb, 'n 'bout 205 hp with a 4bbl. carb,...

 

[Jprevat]

That's pretty close ratings to the vortec setup. I finally got the engine in, buttoned up, and the outdrive bolted on. My timing is off a bit but I got it up and running on the hose and I couldn't be happier. I only ran it for a 45 seconds or so to make sure the water cycled through the engine but man IT RUNS!

 

[Jprevat]

I think it took me about 12 hours by myself from putting the engine on the hoist on Thursday to cranking it up today. So all in all I don't feel like that was too bad.

 

[Jprevat]

So I may have a problem. It looks like my rpm gauge has decided not to work anymore. How do I go about testing if it is getting a signal and where does the signal originate from at the engine. I honestly don't think I could have gotten this far without y'alls help.

 

[Jprevat]

Some of my plug wires didn't have a positive *snap* to them so i am replacing them all with acdelcos this afternoon. Could that cause the tach malfunction?

 

[Jprevat]

Ok I have a big problem. I have a wonderful internal rattle going on. I think it is a cam bearing or my balance shaft has a wobble.

What's the best way to open up this engine to get to the problem area? Do I pull the front cover, intake, and oil pan to get full access?

I don't have any water or metal in the oil so nothing has grenaded yet.

 

[Bondo]

How do I go about testing if it is getting a signal and where does the signal originate from at the engine.

Ayuh,.... The tach gets it's signal from the coil's (-) terminal,.....

What's the best way to open up this engine to get to the problem area?

Just pull the intake 1st to see if ya can find the problem,....
Ya might have to go deeper after that,....

 

[Jprevat]

Ayuh,.... The tach gets it's signal from the coil's (-) terminal,.....

Just pull the intake 1st to see if ya can find the problem,....
Ya might have to go deeper after that,....

Ok I'll be doing that soon. Would it be worth while to pull the belts and see if any drive components are causing it?

 

[bruceb58]

You likely have the EST ignition. The tach get's its signal from a connector on the coil.

There are 2 connectors. One of the connector goes to the distributor. The tach goes to the other one. There should be one grey and one purple wire on it. The grey wire is the tach wire.

 

[Bondo]

Ok I'll be doing that soon. Would it be worth while to pull the belts and see if any drive components are causing it?

Ayuh,..... I assumed you had,...

Rule out the easy stuff, before ya go deep,...

 

[Jprevat]

I will be in the morning and I will update after. Thank you again.

 

[Lou C]

Also are you sure the rattle is internal, could it be from the valve train? Like a collapsed lifter? Does this engine have an adjustable valve train? as in the old style stud and nut rocker arm set up? That's what's in your pic above...