I have bought a 87 b2600i 4x4 with 140k on it has new: head, exhaust(no Cadillac converter), and just put a new weber carb on it. The weber brought it from about 6mpg to 16 but the problem is it is burning oil like crazy a qt in less than 100 miles, no engine leaks, and compression is good 150+ on all valves, spark plugs look good.... I was going to rebuilt the rest of the engine but with good compression and new head and reading many things on the internet saying the same thing and didnt help... I need help!!

 

replace your gaskets on the top end this worked for me on same truck

 

Which gaskets to be exact?

 

I Re did all if mine just wasn't missing around on a used truck the only thing that's not new is my block everything on my Mazda is new but going to tear it all apart for full off frame restoration.

 

"Gaskets at the top end" "all of them" is a bit vague. Sarah Palin got in all kinds of trouble when Katie Couric asked her what papers she reads and she answered "All of them."

So did you mean the valve cover gasket? Or did you mean the valve guide seals?

And someone please tell me what a "Cadillac Converter" is. Is that the stuff you put into your tank and it turns any little car into a Cadillac?

Tan

 

no sorry the stuff wont turn your mazda into a cadillac.yea the valve cover gaskets.i did mine from there up to solve the issue and then i put in a brand new weber and pace headers.

 

At 140xxx miles you put a new head on it?? At 160xxx my Mazda blew a head gasket and my mechanic told me I needed a new engine, said putting a new head would blow the rings out because of the new compression.........before I met my wife she drove a Hyundai Accent and at 160xxx timing belt went out, valves shot ya da ya da......her mechanic did put a new head on it BLAM O!!!!! Now her cars goes through oil like crazy, she got rid of it of course but yea, anything over 100xxx your risking of blowing rings,bottom,etc.... good luck

 

The 86 and 87 had a bad motor design and requires alot of work to make it reliable. And yes these motors arr designed to grenade if one thing goes wrong. Its usually the head, counter balance shaft, and the crank. If one goes they all do

 

or try using the heavy stuff. purple oil at 15W 40 can stop leaks and help keep the engine cooler to prevent internal damage

 

that isn't always the case.. 90% of my vehicles have greater then 200,000 miles, and I've done heads, & headgaskets without issue.. The HUGE problem is the Mitsubishi engines are garbage when they break down..

Pre-1990 B2600's were that pesky Mitsubishi (Mitsobitchy) motor.. your best bet is to replace the mitsobitchy motor, or get a 1990+ B2600 with the Mazda engine..