Exhaust manifold plastic guide sleeve

Hey guys, I’m about to take off my exhaust manifold to get to my PCV valve (which is in absolutely the stupidest place I have ever seen) and just to check everything out, on my 1996 Mercury Mystique 2.0L automatic. Anyway, I know I need a new gasket when I reinstall the manifold. However, the Haynes manual also states (in very clear language) that I must also install a plastic guide sleeve when I reinstall the manifold. See page 8 of this slideshow: http://www.slideshare.net/kerryprinceuk/motor-zetec

The question is: do I actually REALLY need this thing? If I do, where the heck do I get one of them? There are a lot of Zetec engines out there, so I figure this part should be pretty easy to find but my googling has failed me here (checked all the big auto parts store sites, RockAuto, etc).

I’m probably, as usual, too worried about doing this simple job right, but I do enjoy doing things the right way and not having to do them twice (and I’ve never taken off an exhaust manifold). Thanks for your advice.


I wouldn’t worry about it…

Those guide sleeves make sure that the ports on the exhaust manifold aligns perfectly with the ports on the head.

Unless you’re looking for more horsepower from the engine, and with it being a 1996 vehicle, and if rockauto doesn’t list them, they can’t be that important.



Cool, thanks. That’s what I figured but I thought I’d run it by you guys before I did something possibly dumb and had a totally misaligned manifold spewing exhaust gas.

Mostly I just really hate draining coolant in the winter and didn’t want to have to re-do the job.


I have a hunch once you remove the manifold, you’ll find the sleeve will be on that lower right stud, just as in the picture

I suspect Ford wants you to reuse the existing sleeve

That’s probably why you can’t find it online anywhere

The manual does say to fit a new plastic guide sleeve, but if all the thing is doing is acting as a spacer then I don’t reckon it matters if it’s old and worn out. I’ll reuse the old one, or ignore it if the guide sleeve isn’t there. Thanks again!

No experience w/your engine, but I’ll add to the above comments that is critical there be no exhaust leaks once everything is put back together, especially no leaks there. Number one reason is passenger safety. Next is that during normal piston action there is a brief time when outside air can be sucked into the exhaust stream if there is a leak, and this confuses the heck out of any downstream O2 sensors, and will cause the ECM to miscalculate the fuel/air mixture, yielding poor performance, poor mpg, and often a check engine light. This is a problem you don’t want to introduce.

I’ve never heard of having to remove parts of the exhaust system to service a PCV valve. Wonder who came up with that idea?


What you stated is true about air being sucked into the engine thru the exhaust manifold can cause problems. But not with the O2 sensor. The air is being drawn in by the downward motion of one of the pistons, so the air is going into a cylinder and not down the exhaust pipe.

But what can happen is if cold air is drawn into the engine thru the exhaust manifold and when it enters a cylinder it can crack a valve.

This happened with a co-worker who knew there was an exhaust manifold leak and wasn’t concerned about it. That was until they were driving on the freeway at 70 MPH and the temperature dropped to -10 degrees.

Guess who got to remove the head to replace the valve?


@GeorgeSanJose Ah, thanks for the advice. I’ll be sure to check it well once it’s reinstalled. As for the PCV valve, it’s the dumbest placement I’ve ever seen (especially for such a regularly serviced component). On the V6 model, you have to remove nothing to access it, though the air plenum sort of gets in the way. On the 4-banger you have to drain coolant, detach the upper hose from the thermostat housing, detach the radiator bypass hose, remove the exhaust manifold and its heat shield. I’m just going to swap the damn thing and all the hoses regardless of what it looks like.

@Tester I didn’t realize an exhaust manifold leak could cause such havoc. Good to know!