2000 Grand Marquis Miss fire but no CEL?

[miamibob]

My apologies for the double post earlier. I just went ahead and bought everything that I could pick up locally at the Auto Parts store. Turns out they were having a good black friday special, unfortunately I could not buy the heater hose assembly underneath the intake manifold. Now what I am wondering is if I tackle this chore myself, or should I take it in.

The majority of the places are quoting me around 550-600 in labor, and thats if I bring in my own parts. They were quoting me over 1K for parts and labor. My question is how hard is this to replace? Just time consuming, or should it actually require a mechanic to replace it?

Check out the various videos on YOUTUBE and some auto parts online companies (A1 Auto Parts, etc). After that (it ALWAYS looks easier on the videos) see if you are comfortable enough to tackle it.

[MercMan]

The "safety Bracket" towards the firewall on the drivers side, has a PITA nut to get to. Does anyone happen to remember the sizes for those nuts?

[IPreferDIY]

The double posts are a known issue. Not your fault.

Changing the intake manifold is definitely a full day project. I think the most technical part is using a torque wrench, so if you know how to use one, you should be okay. I have no idea what your background is, so I'm hesitant to "encourage" you to do it yourself. It really comes down to what you're comfortable with. My father used to own a business with a modest machine shop, and I worked on other types of machinery before working on cars, so I can usually figure things out and deal with problems. I also live within biking/walking distance of a Canadian Tire and a Ford dealership, so I can usually deal with 'surprises' that come up. If you give us advance notice of when you're going to do it, I and/or others might be able to confirm we'd be available for questions that might come up. Of course, if you make lots of money and don't like getting dirty, might as well get someone else to do it.

I don't recall the size of the crash bracket nut, but it's not so bad if you take the windshield wiper motor stuff off to access it. It's the access problem that makes it a PITA.

[MercMan]

I am hesitant to state my mechanical abilities, however I did work on fighter jets (F-15's) for 4 years, but I still don't know if this qualifies me for the task at hand. However at this moment I am too far into the project to turn around, I have to get it done now before Monday or my wife might kill me. Oh and just another little bit of information, the injector tabs were so brittle I think that have of the locking tabs snapped off. I hope that this doesn't bite me in the ass.

[IPreferDIY]

If you're comfortable swinging a wrench, you shouldn't have any problems. Those cheap injector connector things are a common problem. I doubt a mechanic would have any better luck with them. I haven't had any issues with them loosening off. At least when you do things yourself, you know what the issues are. I also like taking the time to do the sorts of things that a typical mechanic wouldn't (eg. clean up the bolts and whatnot, apply rust inhibitor). I'll likely be around all weekend and will make a point of checking for questions.

[MercMan]

Yea I am done for the night, i will pick up again first thing in the morning. I think that I might have opened Pandora's box with this though. I didnt realize how bad I have been neglecting the Merc. Now i am replacing everything that gets in the way, at least i wont get double charged for it though. Thanks again and if anyone happens to remember that nut size before tomorrow morning it would be appreciated.

[IPreferDIY]

Here's an excellent link with lots of photos, including of the crash bracket:

http://www.idmsvcs.com/2vmod/intakemanifold/replace/pictures/

I remember seeing this one before. It looks like he used 13mm and 15mm for that area. I prefer to use standard sizes where possible since I find they tend to fit more snug (eg. 1/2" instead of 13mm).

One useful tip was removing the EGR valve from the throttle body only and leaving it on the tube. You would most likely need a replacement gasket when putting it back on the throttle body, but the gasket shouldn't be more than a couple of bucks.

Here's another useful link that indicates you might need a 10mm:

http://www.crownvic.net/ubbthreads/ubbthreads.php?ubb=showflat&Number=801206&page=1

Regarding your earlier alternator bracket query, I don't remember seeing an easy way to modify the original bracket, but I could be wrong.

[MercMan]

I finally got the intake manifold off. The first bolt was a 13mm or 1/2 and the 2nd was a 15mm. What I didn't see in any of the other write ups was that there is 2 13mm nuts initially holding on that bracket that is attached to the crash bracket, if this makes any sense.

Now I noticed that the heater assembly that is under the manifold is metal, so should I really bother changing this? It seems like it is in pretty good condition and I don't like fixing stuff that isn't really broke.

Also how hard is it to change the water pump? This is another one of those things that I'm not sure if I should change, but I am sure that this is on its last leg and probably the original water pump.

I'm off to the auto parts store to get an upper and lower radiator hose, along with a torque wrench. All I need is 18lbs to torque the manifold back on correct? And what type of radiator fluid should I get?

[IPreferDIY]

I vaguely remember something being secured to that crash bracket. Can't recall the details though.

The thing to look for on the heater tube under the manifold is little blisters of corrosion. I had a bit but just scraped it off and applied rust inhibitor. So far, so good. I'm thinking a thin layer of grease might give the same protection, but don't hold me to that one. If mine fails, I'm figuring I'd like to try putting in a PI manifold, which would require a different heater tube and nipple anyway. In the interim, I'd cut the tube at the front and route some heater hose around the outside of the engine.

AFAIK, the only PITA with changing the water pump is draining the antifreeze, which is easy enough through the rad drain valve. It seems to be the sort of thing that could be done as a standalone repair. I never bothered changing mine, which currently has about 111,000 miles on it. I think the only issues you get with the water pump are leaking and maybe noise, so if you're not experiencing those, then it wouldn't be urgent.

The instructions that came with my manifold said 18 ft-lbs, and don't forget to do it in the proper sequence. I like to do it in steps, so maybe snug first, then 6 ft-lbs, then 12 ft-lbs, then 18 ft-lbs (or something like that). Also, you're supposed to double-check the torque after the engine is warmed up and the gaskets have softened a bit.

Use the regular green antifreeze. I think you can get a five-year version if you don't want to change it every two years. DO NOT UNDER ANY CIRCUMSTANCES USE THE ORANGE CRAP!!

If your cooling system hasn't been fully flushed in awhile, here's the way I'd do it:
1. disconnect the upper rad hose from the rad
2. tape some kind of plastic sleeve over the hose and put the other end into a large bucket (maybe have more than one on hand)
3. fill the rad/reservoir with distilled water
4. start the engine and let it warm up
5. when the coolant cycles, pour in distilled water (at ~$1 for a gallon jug, might as well get 4-8 jugs)
6. keep doing that until what comes out looks clear enough for your liking
7. then start adding straight antifreeze until you get to 50/50 (eg. if the entire capacity is four gallons, just add two gallons of straight antifreeze).

[MercMan]

Are all the intake manifold bolts the same length, thread, size, etc.? If so do you know how difficult it is to get my hands on another manifold bolt, I seemed to misplaced one.

[IPreferDIY]

I'm just going from memory here, but I recall that all the intake manifold bolts were the same except the one on the crash bracket and the two long ones for the thermostat housing. This is the sort of thing I would get at a U-pull yard for free. A regular junk yard might let you get a few, or at least get you a few. I'm not sure if stores or dealers would have them in stock even if they carry them. I'm not good with the variations over the years, so I don't know if anything up to 2011 would work. Our cars typically fall within the 98-02 year range, but you might get lucky with those bolts.

[MercMan]

I got a regular bolt for the time being (same thread and roughly same size), and I put it at the front passenger side (easiest to get to later on). Torqued it to 18ft lbs, it will just be a temp thing until I can find an actual bolt. Hopefully it works out alright.

[IPreferDIY]

That's among the things I might've done, though you might want to put it more towards the middle so that the only leak potential would be air and not coolant. If the bolt is not sloppy in the hole, it should be okay in any event. When you get a proper one, you should probably wait until the engine is cold before you put it in.

[MercMan]

Does the crash bracket bolt go in the number 3 or 7 intake manifold spot? If so I might have found my missing bolt??

[IPreferDIY]

I don't know which spot offhand, but it does take the place of one of the regular bolts. I had actually thought that might be the explanation for the missing bolt. Hopefully it is.