1998 4.6 hse over 100k miles

[diveman]

my 1998 4.6 hse has over 100,000 miles is there anything to look out for and how many miles can this vehicle last?

[Mr Tj]

Depends on how long you want your piece of string.

My 1996 4.6 has 120,000 and is going strong (still looks like new [on the outside[).

Like anything else the importance of regular servicing becomes even more so as mileage increases. The extra cost of 6-monthly visits to your local dealer is cheap insurance. Also it's probably worthwhile going with an extended warranty (as always(.

The 96,000 mile service is a must. Replacing all the rubber under the hood is a very cheap way of prolonging part life.

Known problem spots around the 100k area are the hoses (see above), the fuel pump (mine gave out at 115k), and the heat exchanger core (very wet front passenger footwell). Other than that my guess is that with a bit of regular tlc the engine block is probably good for 180-200k (if not more), and the body will last longer yet. I've not really seen any data on how long the chassi holds up, that really depends on how salty the roads get in winter etc, though looking at the UK classic population, I'd say 15-20 years of service shouldn't be improbable by any means.

HTH
Staffan Tj.

[glenncof]

I have 1991 RR with 169K and have some suggestions.

1) My 3.9l runs dirty and there is a dinky oil filter off the front of engine. I can tell this by the weight of filter (old vs. new) as I change the oil myself. (For reference I also do my Porsche 911 and a 1997 Chevy Tahoe).

At about 94K I started getting tappet noise and only 1K miles per quart.

I started oil changes every 1K with double size WIX 51459* (there is a FRAN cross reference also or PH1 will do but only 50% larger than stock). Oil GTX 20W50 in Northern California. Did this about 10 times then gradually increase to every 3,500 miles adding only one quart after 1,500 miles.

* This filter cleared the front cross member but needed rubber strap wrench.

NOW it's running SWEET, almost inaudible at idle.

2) Another high mileage suggestion; I have been draining the transmission every "other" oil change. Sooo....simple,a drain plug in the center of transmission pan. Do it at oil change so no extra mess.

I assume previous owner changed it at 30K as scheduled and I had it changed at 60K. I started this at 148K and have done 5 times so completely flushed; much smoother shifts, running quiet. I'll probably back off to every third oil change.

Total capacity is 8 quarts but only 4+ quarts come out. Balance stays in torque converter. Dextron III ... buy gallon + 1 quart. Pour in the gallon and top off ~1/3 quart after checking level (mine is cold idle in Park after shifting thru the gears).

I wish I had known how easy this was and started sooner. These transmission are expensive and the gallon is only Dextron III is $6 at Kragen.

I do not replace transmission filter since it requires removing tail pipe from exhaust manifold <can you believe it> and a bolted cross member. The repeated changes not only refreshes fluid (50% each time) it gradually transports out the very fine partical sluge that resides in the bottom of the pan. (I changed my 1997 Chevy Tahoe at 105K and wiped it out with a rag. Unfortunately the chevy has no drain plug so changing is Very Mess Job.)

Don't completely FLUSH as I have heard of some problems. The above is nice gradual cleaning. You'll see the fluid get more clear each time.

I can easily see the engine lasting another 100K.