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Used 99 Mercury Marquis with 90K miles


123DanT
12-10-2009, 03:09 PM
A family member is looking at buying this and I not familiar with these models. Could someone give me the top 5 items to look at or be aware of when evaluating it before making an offer. Thanks

Blue)(Fusion
12-10-2009, 06:32 PM
Great choice in vehicle (coming from a 22 year old, too)!

Some things to look for:
Intake manifold - The factory plastic intakes are prone to rupture at the front coolant crossover and the plastic nipple the heater core hose extends from. You should replace this intake manifold with a revised manifold with an aluminum coolant crossover regardless of it's condition - it is a time bomb waiting to go off at the most inopportune time.

Ball joints - Although a typical wear item, the factory ball joints are sealed and they usually last a long time, but if you hear any squeaks coming from the upper or lower ball joints, expect to have to replace those soon. Replacement can be around $500 or more. If you do it yourself, quite a bit less.

Worn timing chain guides/tensioners - This is a bigger problem on ex-police vehicles due to high idle times, but nonetheless, this is something to watch out for on all 4.6L engines. Since, IIRC, 1998 Ford redesigned the guides and tensioners to use plastic instead of steel and when the plastic wears through, the timing chains start destroying the aluminum behind it and can cause a chain to jump a tooth. This can be identified with a "sewing machine" sound from the front timing cover of the engine. At 90k miles on a non-fleet car, I wouldn't suspect this being a problem for you.

Air ride - If equipped with air suspension, ensure it is operating. With the key in the ON position, you should hear the compressor turn on when weight is added to the rear of the car, and should see it rise and fall as necessary when weight is added/removed.

That's about all I can really think of that's not really reaching. Everything else are things to check on all cars - shocks, alignment, fluids, brakes, tires, lights, filters, spark plug life, etc.

The Silver Goat
12-17-2009, 08:50 AM
Blue - where'd you get the intake from? I've got a 99 and with winter here that's the last thing I need to have go running around town. Also, is there a link to a set of instructions?

Blue)(Fusion
12-17-2009, 09:05 AM
I got the Performance Improved (PI) intake manifold swap kit from ADTR (http://adtr.net/shop.php?page=intake) for a slight improvement in power. These are the intakes used on 2001 and newer Mustangs and our car 4.6Ls. They are almost a direct fit, but some extra work is required to get these to work.

If you wish to go with Non-PI which originally came in our pre-2001 engines, get a Dorman NPI manifold from ebay or any other online retailer. They should run roughly $200-$220.

A good howto for the original NPI replacement is located here (http://www.autoclinix.com/Manifold.htm).

123DanT
12-21-2009, 03:20 PM
Thanks Blue,
Great info! I'm going to tell them about the intake manifold and air ride issue definately, because this can has been sitting around for ~3 years and only used when there other vehicles broke down. Like you said also on the ball joints . . . could be expensive. Would be ok if there was a guy in the family that could work on it, but they don't that experience.
Thanks again.

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