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Discussion Starter · #1 ·
My new to me 1995 4.0SE RR (133k) runs extremely well. It is smooth, revs smoothly, NO smoking during start, acceleration, gear change, revving, etc. It has two problems: Most concerned about a light clattering sound seemingly coming from the engine. I though maybe catalytics? (Went through them on Classic which sounds like engine is falling apart) but these were replaced under recall in 2002. Sound is light. Even with windows down you can't hear it when under way. If you are in a tunnel or next to building you can hear it. With hood up, you can hear it. Also, listening next to the fenders you can hear it well. Very hard to pinpoint sound. Immediately upon starting when cold for maybe a minute you don't hear it. Then it comes on. Kind of like "tap-tap-tap-tap" The noise DOES increase according to RPMs. Valves? Rovers North (just from description) said probably not a liner. ANy ideas?

Other problem is sometimes you start truck and then it dies. Always starts and runs next attempt. Coil packs just replaced, plugs replaced, air cleaner ok. Ideas?
 

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On the second problem, it might be the first sign of a deteriorating fuel pump. These have a tendecy to go around 100-120k from what I can tell (my '96 110k 4.6 was the 4th our local dealer had seen with that issue this summer).

The best way IMO to (cheaply) tell is if the starting problem gets worse the longer the car sits (what tripped me to the dealer was coming back from a 1-week trip away, and having to take 10 goes to start).

Is the ticking intermittent, or all the time the engine is running?
 

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1) Light claddering. I have 1991 RR with 169K and have heard light claddering at idle. Sounds like a metal flap perhaps controlled by intake manifold vacumm. Rev engine goes away. It has been doing this, oh maybe 50K+ miles so I don't worry.

If someone knows what it is I'm interested.

2) I had a intermittent dying at idle. Of course, it would only happen when my wife was driving ...:) Finally died on me;

Air Stepper Motor is what sets idle (off the back side of manifold). It's controlled by ECU which sends pulses to regulate idle RPM.

It regulates the amount of air that by-passes throtle plate. It gets gummed up with oily muck since it pulls air after filter near the point where crank case blowby gets sucked into throtle body (before throtle plate).

This can be cleaned but it's delicate and not fully reliable (clean and see if problem goes away). See below for low cost repacement sources. I would go with AC Delco since it sounds like it has a better spring.

Clean out the mating suface also with carb cleaner and cotton swab. Good time to clean out screen on blowby connection to valve cover, looks like a small 2" can that screws into place with black hose going to other side air intake.


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http://www.rangerovers.net/rrpartsv.htm#stepper

Idle Air Bypass Valve (ETC6660):

The genuine Range Rover Idle Air Bypass valve (now fetching rather heady prices as the dollar has declined in value) has long been available for less than dealer prices from aftermarket sources; as of November 2003 it can be had for $169.95 plus shipping at Atlantic British and British Pacific, or $167.79 with free shipping at Speedycarparts.com. The Rover Connection now has an aftermarket one for $110. The lowest price I have found recently (November 2003) for the generic replacement (described below) is at AutoPartsGIANT.com for $36.58!! (search for fuel injection parts, 1989 Chevy Astro V6 -- subcategory idle speed control parts).

If you are interested in experimenting a bit, cheaper alternatives can be tried, at considerably lower cost than the genuine part or those sold by the traditional Rover aftermarket suppliers. Salvador, of Baja Rovers, Mexico, found that as we suspected the idle air bypass valve/stepper motor is indeed a GM part #25527077. He found the Napa part number is 2-1738. Phil Tetzlaff reports finding this part at his Boulder Colorado NAPA store, but later exchanged it for one manufactured by AC Delco, part number 217-437. It appeared to be of higher quality (in casting density and spring strength) than the Napa brand part, and indeed appeared to be exactly the same as the Land Rover part. The final kicker was that while the "genuine" Land Rover part is well over $150, the Napa part cost was $51.99, and the AC Delco only $38.51!" (However, prices have gone up considerably since then due to the fall in the dollar). Greg Olma suggests “Go to a junkyard and take your pick from GM 4 and 6cyl. I use PB'laster to clean em.” Richard Atkinson reports that this is perhaps the most popular GM idle air motor, and is eqiivalent to AC Delco part number 73312A, He says it also crosses to AC 17085051, 17086051 and 1717111288, amongst others, which were fitted to almost all 3.1L V6 from '90 - 95, '85 - '86 2.8L V6, as fitted to Cavalier and Celebrity, '85 -'92 5.0L and 5.7L V8 Camaro, etc. etc.


I have recently done more research into this mysterious part. Searching the NAPA parts directory, I did not find this genuine AC-Delco part, but they had an equivalent off-brand "Mileage Plus Fuel Idle Air Control Valve" part number MPF31738 for about $40 at Napaonline.com. (Glenn Coffman went to NAPA recently (June 2004) and they gave him a P/N 2-1738 for his 91 RR for $57). I found they had an alternative matching Echlin part number CRB21738 for $52.99 (a better known brand). I also discovered that the GM Part number 25527077 is the AC-Delco part number 217-437. Various internet GM parts sources sell it for around $50.


The lowest price I have found recently (November 2003) was at AutoPartsGIANT.com for $36.58!! (search for fuel injection parts, 1989 Chevy Astro V6 -- subcategory idle speed control parts).


Update July 2004: Cory Novak found that partsamerica.com & sister store Advance Auto have the Idle Air Bypass Valve for $27.99 in stock most of the time it is GP Sorensen 779-10003 & item number 5012678.
 

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Discussion Starter · #4 · (Edited)
Thanks for replies. Regarding the starting / stalling problem, to clarify, It will ALWAYS start on the second try. I believe I have found the problem with the clanking sound: Pikes Peak Rover (Very helpful despite fact we live on opposite side of country) says that a common problem is the valve rocker shaft wearing, not getting enough oil, clattering...etc. Easy $60 fix. Sound does not go away when revved. From inside the car, engine always sounds smooth. I got the Classic going yesterday so I could park the two side by side and compare. The Classics' 3.9 is pressurizing and burning coolant, other than that it runs well. (Not driveable, engine is basically junk except for yard drives) When it starts and idles, it sounds good, better than even the new 4.0! Fortunantly, there is no real problem with the 4.0. By the way, the idle stepper motor, etc, is a little different on the 4.0. I did clean it, it was mildly dirty. The car seems to start faster (still stalls sometimes, though) but now the idle oscillates a lot. Sometimes it will idle at a steady 1800 RPM! This is all after cleaning the part. The PCV routing is different too. No longer have the can that unscrews from pass side valve cover, but a short little breather hose right off the throttle body and into the driver's side valve cover. No mesh inside. I cleaned this as well.
 

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hi all. the clattering noise could be a couple of things. firts i would check the exhaust manifolds 4 hairline cracks i have seen that before also there is an old tsb for rocker shaft ticking noise. what hapens is the tappets in the ball socket of the rocker arm comes loose and makes a tapping noise however this is not an issue that will make your rover die out. you should have it scanned for trouble codes even though the check eng light isnt on it can store sporadic codes in the ecu :buttrock:
 

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troverman,

Your comment about the 1800 rpm reminded me that my 1991 RR would sometimes idle high also. The spring on my stepper motor is so weak I'm surprised it didn't fail more often. I'm still suspicious it may be the problem.

It and the blow-by hose were the last things you touched, right ? Check for air leaks. Sometimes old hoses don't mate as well after being disturbed and need a clamp.

On my 1997 Tahoe, the blow-by hose came loose (how??) and the truck barely ran. It has a PCV value with a ball in it (i think it is flame trap). The 1991 RR only has the screen. This is not likely to be the source of dying at idle.
 
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