Engine rattles and sounds like a Diesel

[Red Panda]

So my parents gave me their 98 Explorer that's been in the shop forever, it's had issues trying to pass emissions, but it has never sounded this badly.

it's the OHV 4.0 with some 327k on the engine

They've had the 02 sensors replaced, intake manifold and and some other things done. I drove it home from the shop two days ago and it was rattling something awful, the engine was shaking all over the place, there was a hissing noise coming from an unknown area of the engine, and it sounded like a Diesel.

It dies on inclines and that's what happened to me yesterday when I was trying to get it to one of my mechanic friends. I died in route 50 and ended up getting towed home

I changed three spark plugs, these are the old ones, and it's leaking oil like water.
there are puffs of smoke coning from the oil spout, and the mechanics left alot of things unbolted like my dipstick for one.

it's raining right now so i might not be able to get to it today, what do you think is up ?

 

[my98nnj]

Time for a rebuild on that motor.

 

[jdtractor]

i was thinking the same, think the motor has finally given up the ghost lol.

 

[masospaghetti]

The OHV can be noisy even working properly (and often described as sounding like a diesel). Mine has been somewhat noisy from when I got it until now, from 93,000 miles to 174,000 miles. It's mostly at idle though.

Regarding the other issues, where is it leaking oil from? And check your PCV valve, if that is clogged up you will get a lot of pressure in the crankcase (the puffs of air from the oil spout).

 

[Red Panda]

It just clicks and won't turn over, battery and alternator are new

Where are the Pcv valves ? Although it might be too late, oil is coming from the bottom and one of the valve covers.

 

[Red Panda]

I'm already calling it a project and planning on buying a new engine later this year

 

[lobo411]

I'm already calling it a project and planning on buying a new engine later this year

Honestly, I'd dump it. At the scrapyard if necessary. This is a classic money pit situation, and the vehicle isn't even worth the cost of a tow. Sure, you're going to put in a new engine. Are you also going to put in a new trans, new suspension, new rubber parts, new vacuum lines, new blower motor, new heater core, etc...?

Save the money you were going to spend on a motor and find a nice Gen II with 100k on it or so.

 

[masospaghetti]

PCV valve is on the driver's side valve cover, near the engine firewall. There's a little rubber hose that runs from it to the intake manifold (its kind of S-shape hose). The valve itself just pulls right out and only cost a few dollars to replace.

The valve cover gaskets commonly leak and by itself isn't a major issue.

 

[koda2000]

in it's current condition, it's worth scrap value. i wouldn't bother replacing the engine. scrap it. if you must have another Explorer, take your money and look for a 2000-2001 V8. where i live they can be had for around $2000-$2500 (some are more, some are less). if you find one in decent condition, that's been maintained, it should be good for 300,000 miles. expect to have to put some money into whatever you buy, as it's a 14 year old vehicle after all, but the V8 engine and trans are pretty bullet proof. everything else is fairly inexpensive to fix if your handy and there are plenty of Explorer's in the salvage yards. the gas mileage sucks, but it's not much different from the V6's.