On some of the empty roads I travel, 100mph barely keeps up with all the folks in their newer 300hp+ family sedans. But I'm wondering, will running a steady 100mph in a '92 740 hurt anything? The motor is in pretty good shape, with a very very slight #1 piston slap when cold, which disappears after about 90 seconds. The motor always has fresh Mobil 1 5w30 or 10w30 in it with a mann filter.


Edit: the motor has about 140,000 miles on it, and the valves were adjusted about 20,000 miles ago.

Mobil 1 makes a 5/40 oil that would offer better engine protection at sustained high speeds for you than the 5/30 or 10/30. It is marketed here as 'Truck and SUV' oil, but is a very popular viscosity oil for cars in Europe. I use the Shell Rotella T syn 5/40 year round in my 240, only because it is cheaper and easier to find than the Mobil 5/40.
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'94 940 150k, '86 240 170k, '72 142 KIA, '70 144 KIA, '69 144 RIP

My '89 740 turbo did just fine at 100-110 MPH top speeds at Pocono and Watkins Glen this Summer. (not to forget the yo-yo stress of braking hard to as low as 40 MPH for slow speed turns)

Two things I'd suggest to you, though:

Read up on oil issues at:

http://www.bobistheoilguy.com/

Then send a sample of your oil for lab testing at:

http://www.blackstone-labs.com/index.html

Then stick with conventional motor oil (mineral, not synthetic) for a while while treating the engine with Auto-RX to get it cleaned out:

http://www.auto-rx.com/index.html

The lab results from Blackstone will tip you off about any problematic wear issues. Auto-RX will rid your engine of sludge, loosen up the rings, etc.

(After two treatments, you can switch to synthetic oil, which I believe cleans better then mineral oil, or, stick with conventnional oil and maintenance amounts of Auto-RX)

I bought this car sight-unseen. When I tested the oil Blackstone told me it had high levels of iron and copper. These indicate high wear on the bearings and rings.

With the interventions I mentioned above, these levels are coming down.


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'Can't understand why people abort Volvos, either' '89 740 Turbo, 122,000 miles

Hi Zee,

Why would he switch to dino oil when he's already using synthetic? I would think he'd be just fine with the Mobil 1. I just suggested he use a heavier weight for high speed driving though (engine working harder)...
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Chris. Halifax N.S. '91 745Ti, 291K km and '91 745 NA, 385K km.

Why use dino oil with Auto-RX?

It's their idea. The web site says conventional oil carries the treatment better than the synthetic.
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'Can't understand why people abort Volvos, either' '89 740 Turbo, 122,000 miles

I just did an 8 hour trip in my 88 744t with a 5 speed and 250k. I ran about 95 the entire time and the car did fine although I felt like I was pushing it a bit much. It's a lot more comfortable at 80-85.

I also had a six cyclinder volvo motor in the trunk.

Jes

it's not gonna break unless the oil is black & abused...remember they(the factory)run the engine at maximum rpm's for a long period of time to see what's gonna break...guess what nothing breaks/its been built for years...

I took 2 seperate car's on 100mph + trips for long periods,

one was an 89 745 and the other was an 87 765

Both performed well, though both were very well maintained too, complete front suspension redone, at least H rated tires all around ETC ETC, i felt comfortable doing 100, NOW becarefull and test this speed before you really think it is okay it will take a hell of a lot of time to stop a volvo doing 100mpg, i do 80mph on a daily basis here in So Cal and that takes long enough to stop, the only time i have done 100mph is in the middle of the night driving home on a 8-16 lane freeway which is properly paved ( a rareity here in so cal but the 15 is still in good shape ).

If I remember, my '88 244 would hit 100mph and the RPM's would be in the 3-4k range. I would figure that your gas consumption would go up, because from what I remember, the B230F will have to work hard just to keep up that speed. Sedans such as a V6 Honda Accord won't have to work nearly as hard. The B230F engine, however, won't have any big issues with hard work, although your gas mileage could suffer. The 854 I have now can do 100MPH without even working up a sweat.
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'94 854 N/A.

I think my 740 is doing 4500 rpm at that speed, even with the locking torque converter. It's geared pretty high, but that's the way they came. I guess they were trying to get more low end torque to sell cars during test drives.


I know what you mean about your 854. I have an Integra that's just getting ready to go at 100mph. However the Volvo is just more comfortable and has more space for very very long drives.

Yep, they are geared on the high side - otherwise, folks would complain even more about the acceleration. Consider swapping in a taller rear end (off a manual tranny car) to lower the revs. Also, if you don't mind the speedo reading off, put on larger tires. 205/70/15 is about the biggest you'd want to go - it's the front strut spring cup that's the limiting factor.

-- Kane
--
Blossom II -'91 745Ti/M46 ... Bubbles -'74 144GL/BW35 ... Buttercup -'86 245GL/AW70
The Wayback Machine -'64 P220/M40 ... The ParaBox -'90 745GL/AW70

Hi ioio,

Nope, should be just fine. Just make sure you're cooling system is in good condition as well as your transmission fluid (clean) and rear diff fluid (synthetic 80W90 would probably be good for high speed). I'd use 10W30, 10W40 or 15W40 in the engine (although Mobil 1 doesn't offer 10W40 or 15W40 I don't think). 5W30 is too thin for high speed driving. I few days ago I drove my 745NA for about 2 hours averaging around 130 kph (~80 mph) and it seemed to be just fine with that. It has Shell Rotella T 15W40 in the engine and Amsoil 80W90 in the diff and rolled 385K km (~240K mi) during the drive :) Oh, if you're doing this often you might consider IPD's VX camshaft (non-turbo) or turbo camshaft (turbo) as it should give a little more power at higher revs. If you have a turbo, make sure you let it cool down a little more then normal (maybe 1-2 min) after this sort of driving as it will get quite hot. Also, with a turbo, you've got some more options for modifications that will help you keep up with the newer cars :) One more thing that you probably know; Don't push your car to higher speeds (higher revs) until the engine has been at operating temp for a few minutes and everything has had a chance to expand. I hope this helps.
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Chris. Halifax N.S. '91 745Ti, 291K km and '91 745 NA, 385K km.

Thanks, that was helpful. The car has no turbo, but I kind of like that 'cause the torque converter locks up. AFAIK, the turbo cars are stuck with slush the whole time, though I have no idea why.

You are correct, there is no 15w40 Mobil 1. There is however 0w40, which new BMWs are coming with from the factory. I'm considering trying that next oil change. I figured it really didn't matter which Mobil1 I had in the pan, as it shouldn't get thin at high temp & RPM, the way regular oils do? I don't know for sure.

Yea, one day maybe I'll throw a new cam in there. When I get time. I've been saying that about my tie rod ends for TWO YEARS now.... sheesh I need a break.

Hi ioio,

Yeah, I think only the late 940Ts had lockup torque converters (AW71L). I wonder what year the non-turbos got it as I'm pretty sure my '91 745NA doesn't have one as I never notice a lock and unlock and it revs pretty high on the hwy (higher then the turbo).

Yeah 0W40 may work, but I still don't quite get these 0W oils. Yeah, you'd think 5W30 would be the same as 10W30 when warm, but this isn't quite true. It's all in the specs and plus the oil will change it's charactersitics to some extent as it is used, even synthetic.....It's kinda complicated and I don't fully understand it... As I said, I use 15W40 in my non-turbo and Amsoil 10W40 in my turbo. Both seem great, although I wish there was an oil that could get rid of damn piston slap! Even a rebuild of my B230FT didn't totally eliminate it!

Careful with those tie rods! I wouldn't be driving that fast all the time with something that is worn.


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Chris. Halifax N.S. '91 745Ti, 291K km and '91 745 NA, 385K km.

I wouldn't drive 100 mph with worn tie rod ends,sloppy steering at high speeds isn't safe!
--
philvo '90 240 204k and a couple parts cars

They're not worn very much, just enough to be annoying to a perfectionist.