98 Ford Explorer 4.0 issue-gonna roll it into a gulley!

[Stinsok]

It had a very rough idle. The code reader indicated a bad 02 sensor. I replaced that, now it runs worse than ever. I also installed new plugs/wires. What now?

[Auzzie-Phoenix]

try cleaning the mass air sensor, and changing air filter. you'll probably want to check out the serpentine tensioner to see if it's applying enough tension to keep the belt on the idler pulley.

As for the o2 sensor code, if it's still lighting up the check engine light, try spraying the connector leads on the cable with maf sensor cleaner. Other things to check/replace to help with rough idle are the fuel filter, and pcv valve.

[briand]

...and, if you have the 4.0L engine, there's a PCV assembly that runs all the way around the intake manifold -- the elbows at the turn are rubber/plastic and often crack after so many years of use.. the replacement from Ford is about $40 or so, or you might find a set of high-temp silicon elbows to replace just the broken parts.

[shadowtippy]

Put a dollar bill on the dashboard before you roll it into the gully. That way, you can say you threw something of value away. (Sorry, I'm not much on Fords.)

[Stinsok]

Really bad news. It turns out the timing chain(s) are the problem. The shop I took it to says they won't touch anything like that on an engine with over 150,000 miles. It will costs more than the truck is worth to repair or replace the motor, even with a used one.

[Tegzsa]

Originally Posted by Stinsok

Really bad news. It turns out the timing chain(s) are the problem. The shop I took it to says they won't touch anything like that on an engine with over 150,000 miles. It will costs more than the truck is worth to repair or replace the motor, even with a used one.

TBH that sounds more like a problem with the shop rather than the motor. Timing belts/chains are a pain, but not if the mechanic knows what s/he's doing. It could be that the chains are worn, or that the tension device (I'm guessing that there is one) needs adjusting. I had the chain changed on an old Rover of mine (with way more than 150,000 on the clock) and it only took 2 hours from start to finish, including a test drive. When I had the belt changed on my old Corolla, it took them 45 minutes.

I wouldn't give up just yet. I think you could probably find a better shop and save your truck.

[HaRd]

Originally Posted by Tegzsa

TBH that sounds more like a problem with the shop rather than the motor. Timing belts/chains are a pain, but not if the mechanic knows what s/he's doing. It could be that the chains are worn, or that the tension device (I'm guessing that there is one) needs adjusting. I had the chain changed on an old Rover of mine (with way more than 150,000 on the clock) and it only took 2 hours from start to finish, including a test drive. When I had the belt changed on my old Corolla, it took them 45 minutes.

I wouldn't give up just yet. I think you could probably find a better shop and save your truck.

This. Are you kidding me that's really bad business on the part of the ship if that's really the case. Most good shops will extend themselves outwards to make a customer happy/make a sale. Also who knows- if that really is the issue and the only one the car will probably run as good as ever for quite awhile onwards.

The 4.0L is pretty much an anchor now but it was pretty reliable workhorse in it's day. My friend just rolled over 200,000 miles in his Explorer equipped with one.

[Gard]

Replacing a timing chain/belt is basic service on ANY engine. I've done it to numerous vehicles, and it just isn't a big issue (it ain't CHEAP, but it's REQUIRED - about to do one on my '03 Honda Element soon).

Any shop that says it "isn't worth it", isn't worth taking your vehicle to. Find a new, reputable shop, get the timing belt changed, and move on.

[kanonfodr]

KBB gives me a private-party sale price of $3k, the cheapest timing chain was $350, assuming 3 man-hours of work at $75/hr = $675 total cost: well under the 60% threshold that insurance uses when deciding whether to total out the car or not. That is on the 4.0 OHV

However, if your engine is a 4.0 SOHC then it has 4 timing chains and it requires an engine pull since one of the is at the back, and it is suggested you have a Ford technician do the work because a) it requires 5 specialty Ford tools to complete and b) that engine is heavily interference'd: if your timing chain is off or breaks loose then hard parts WILL collide and turn your little V6 from a really good engine (I had the SOHC V6 in a Mazda B-series pickup, what a BEAST!!) into a paperweight.

That's the breakdown, and I could almost agree with the shop if you have the 4.0 SOHC, engine pulls add up man-hours quick, plus that parts kit is over $500.

Peace,
Greg

[briand]

...he says his Explorer is a '98 -- that would tend to indicate he's got the 4.0L OHV engine. The SOHC replaced the OHV in 2001 (and later) model year Ranger pickups... I should imagine the Explorer line made the change at/around the same time.

[Stinsok]

It's the SOHC, and I was going to mention the rear timing chain/engine pull deal. If it was a simple front chain job, I'd do it.

[Mike N]

Originally Posted by Gard

Replacing a timing chain/belt is basic service on ANY engine. I've done it to numerous vehicles, and it just isn't a big issue (it ain't CHEAP, but it's REQUIRED - about to do one on my '03 Honda Element soon).

Any shop that says it "isn't worth it", isn't worth taking your vehicle to. Find a new, reputable shop, get the timing belt changed, and move on.

Timing belt replacement is routine, chain or chains are not. Usually something happens to require chain replacement, like a piss poor design (4.0 SOHC, GM's with nylon coated gears) or component failure.

In the OP's case, the timing chain setup is a ridiculous one on the 4.0 SOHC. Some brainchild at Ford decided they wanted either head to fit either bank on that engine. With a standard SOHC V engine this wouldn't be possible..... the cam end at the front of each head would make them side specific...... unless you could figure out a way to get the chain to drive a gear on the back of a head. So, you have one chain that drives the front of one head, and a shaft that goes through the valley of the engine (much like a regular cam in an OHV engine) which drives a chain that drives the other cam from the rear of the other head. Add in all the guides and tensioners necessary for this asinine setup and you have piss poor engineering at it's finest..... but hey, some "engineer" obviously needed to validate his paycheck with this setup. And, pretty much like any truck that Ford builds, the engine needs to come out to service this.

[Mike N]

Originally Posted by Stinsok

It's the SOHC, and I was going to mention the rear timing chain/engine pull deal. If it was a simple front chain job, I'd do it.

There was some sort of recall early on with those for the timing chain cassettes going bad.
Not being a Ford tech I'm not 100% sure what the recall was all about, I do remember those things would rattle like two skeletons f*****g on a tin roof when first started. As the cassettes came apart, the cams would lose time and I believe eventually the chain or chains could jump time and cause rough running.

You're probably long out of range for the recall, but you could call a Ford dealer with the VIN and ask.

[Stinsok]

I am going to take it to the local Ford dealer and get an estimate on fixing it. At this moment, we are looking into selling as-is.

[Pilgrim]

Might think about a wrecking-yard engine. My daughter's 99 Cherokee ate a cam due to a plugged oil passage - for under $2000 I got a local 4x4 place to pull a motor with 10K less miles and swap it.

[Mike N]

I think the cost of repairing it would exceed the value of the vehicle.

Junkyard engine wise you might wind up with the same thing you've already got, especially in a 4.0 SOHC... I'd pass.

[kanonfodr]

Junkyard engines could pay off, esp on a 2001 or newer engine. Of course, you could always put in a 302 and REALLY rev it up

Peace,
Greg

[Mike N]

You never really know what you're getting with a junkyard engine, most yards will tell you "I've got one here with 78000 miles on it for $XXX", when in reality the engine probably has closer to 150,000 on it (BTDT).

If you're willing to swap it yourself and you don't mind the possibility of the yard engine being no good (and having to do the job twice (again, BTDT)) then have at it.

If you're having a shop install a used engine and it turns out to be no good you may be on the hook for the labor to R&R it a second time.

This, of course, is not to say all junkyards are liars or all yard engines are junk, but the possibility of that exsists.

[HaRd]

I'm going to assume that OP has an issue with money but if this is the situation then I'd probably start shopping around for a new car. The whole junkyard thing is still shoddy since it'll be a total engine swap. I mean I've relied on junkyards to get something like a door handle or a directional lamp not a whole new engine or transmission.

The 4.0L Explorers aren't really anything to write home about- pretty poor fuel economy, below average numbers on a spec sheet, etc. I'd probably assess what you need in a vehicle and take it from there...

On an unrelated note the new Explorers are pretty sexy looking- I wish they still made the 2 door because I loved the idea of having a 2dr SUV with a bigger cargo space then a station wagon.

[kanonfodr]

The new Explorers are even more Grocery-Getter than the previous generation, plus I don't know if even FoMoCo can engineer a Forced Induction system (EcoBoost) to withstand the idiocy of the average american driver.

Peace,
Greg