Sigma Tappets

[ccpl]

Hey all, just a question out there to all you sigma owners.

I have a 1985 GN sigma, with a mild amount of work done to it. Recently my tappets started to get a little noisy, but was really nothin to worry about. Then about 2 weeks ago, i took my engine apart and removed my balance shafts with a balance shaft removal kit. I put the engine back together but forgot to prime the oil pump with oil, therefore when i started it up, it didnt get any oil pressure. I realised this after a couple of seconds and turned it off and cranked it over with the coil lead off till it got oil pressure.

My problem is this> Since then anywhere constant above 2000rpm, my tappets start to get really noisy, and then anywhere above 3000rpm constant (for like 1 minute or so) the whole engine gets REALLY noisy, as in u can hear the tappets for miles! however, if i let it idle for a minute or two afterwards, it settles down nicely. Now this to me sounds like an oil pump problem, but i checked over the oil pump when i took it apart and it seemed fine. The only thing i didnt do was use a new oil pump gasket (simply for the fact that no-one in queensland sells them, not even mitsubishi themselves) so i made one out of gasket silicone maker.

Anyone got any ideas to whats goin on? i changed my oil the other day just to make sure, and it was fine for bout 20km, but then it started doin it again.

thanks in advance

[RX22NV]

Have you got an oil pressure guage? If so what does it say. When you said that if you let it idle it settles down, I am just wondering if there is just not enough oil getting around.

You put the bearing looking thing in the hole where the balance shaft was?

[karl_2ltGC]

What oil you running?

[ccpl]

Yeh i put the bearing cup in the balance shaft cavity. The oil pressure guage reads bout 60psi at cruising speeds (2000rpm etc) at idle it reads anywhere between 20-40psi depending on whether its hot or cold. At 3000rpm it sits just above 60psi (3000rpm is bout 100-110km/h) but i do notice it slightly drops bout 5-8psi when doing this. Im running 20w-50 oil.

[MrBishi]

2 thoughts:
-Did you take the tappets off the head? ie is it possible that one of the hydraulic lifters has fallen out?
-Have you tried priming the lifters? Consult a manual to see how it's done but essentially hold a pin in the oil hole (one way valve) & pump the lifter up in a pool of oil. ie fill the thing with oil.

[ccpl]

No i didnt take the tappets off the head, so i dont think the lifter has fallen out. As for priming the lifters, no i didnt think of that, it sounds like a good idea, do u think that would help it?

[rony]

Sounds like running the engine with no pressure has squished all the oil out of the lifters. Not 100% sure but they should reprime themselves.
Theyre probobly gummed up with oil scum or just totally worn out and pumping them dry killed them.

They are around $50 each new from mitsu. Let me know if you find some any cheaper, I need a set too.

[ccpl]

yeh i reckon after a bit of researching that they are just filled up with crap and arent priming properly, would really doubt they are worn out since they are less than 6 months old! but thanks for the help anyways

[Potsy]

Lifters for these can be bought (Non Genuine) for about $11~$12 each.
I got the whole set from Auto 1 .
Same lifters for 4G63-4G54 etc.
Didnt bother priming them, just install and wait about 20 mins at idle. Job done

[mr_sikma]

My sigma runs at 80PSI when nailing it (5500rpm). If that helps?

[Jim]

lifters?? is it a magna head then? early astrons were all adjustable tappets up until the Astron II motor. which do you have?

[MrBishi]

Secoh,
GN sigmas run Astron IIs. An interesting anomoly is that Scorpions and Pajeros of this era ran astron 11 heads with manual tappets.

[ccpl]

yes GN's run astron II's. And yes i have hydraulic lifters. mr sikma, yeh my car used to be around that mark as well, but then it dropped dramatically after a while to 40psi. 1 new oil filter later and she was back to normal. So it definitely seems to me now that my lifters must be gummed up. Might throw a cup of diesel into the oil and run her for 10 mins or so and do another oil change. Thanks for your help guys

[mizone]

I've just changed the tappets in the Magna and recommend you pop the rocker cover off and check the faces of the tappets where they contact the valves. Chances are these are pitted as mine where causing the Diesel engine noisy tappets.

Also prime the tappets in oil NOT as Gregorys suggests in diesel.

If tappet noise continues raise the revs to 3K for a minute and repeat if noise still exists.

$12 for the tappets is an awesome price I paid $20 each non gen. !