Slight Coolant loss on 98 540i

[rph74]

Does any other 540i owner out there have the same (minor) problem as I do?

Every 2 months or so, I get a Check Coolant warning, and find that my coolant level is low by about an inch or so. I don't have to add much, in fact after a short drive and restart the coolant level has risen to an acceptable level. Just wondering if I should be concerned.

[PropellerHead]

Does any other 540i owner out there have the same (minor) problem as I do?

Every 2 months or so, I get a Check Coolant warning, and find that my coolant level is low by about an inch or so. I don't have to add much, in fact after a short drive and restart the coolant level has risen to an acceptable level. Just wondering if I should be concerned.I read in a Jenny Morgan article in the Roundel that there are two coolant hoses near the back of the motor which are prone to leak after some time. They are supposedly hard to replace, but this is supposed to fix the little coolant leak common in older V8 E39's. It could be (and should be) common to all V8's, but this article mentioned an E39.

[NC540]

I had the same problem with a slight coolant loss and corresponding check coolant level two or three weeks prior to my radiator failing. There may be a hairline crack in your radiator that you can't see. The cracks are usually located on the black plastic part of your radiator, which are hard to see unless you examine with a high powered light. If you haven't had to replace your radiator, you may need to do that. Another possibility is the expansion tank may be leaking. IMO, Check these first, then move onto hoses. I was lucky my radiator failed in my driveway.

Good luck.

[rph74]

Great, now you guys have got me worried. My family and I are planning a road trip to Las Vegas (1300 miles one way) in September. I may have to take the Land Cruiser instead now.

Anyway, the radiator/water pump/ AND engine (at a price of 13k to the original owner) were replaced in NOV 01, about 46k ago. So I would hope that the rear hose you are speaking of was replaced at that time.

So do you guys think a radiator replacement is in order here? My concern here is that since it takes 2 MONTHS to lose a little bit of coolant, that something else besides the radiator is the culprit.

[NC540]

From all the research that I've done, it appears that if you had an OEM Behr radiator installed in your car, then they last about 50k miles. Until BMW or aftermarket comes up with a better alternative, I would replace radiator and expansion tank every 50k. I replaced my radiator recently myself and got the radiator for $146 and expansion tank for $57 and did the replacement my self in less than two hours. BMW coolant is around $17/gallon. I would rather be safe with the radiator especially on a long trip--you could get stranded. Just my $0.02

[rph74]

From all the research that I've done, it appears that if you had an OEM Behr radiator installed in your car, then they last about 50k miles. Until BMW or aftermarket comes up with a better alternative, I would replace radiator and expansion tank every 50k. I replaced my radiator recently myself and got the radiator for $146 and expansion tank for $57 and did the replacement my self in less than two hours. BMW coolant is around $17/gallon. I would rather be safe with the radiator especially on a long trip--you could get stranded. Just my $0.02

Hey thanks for your input on this. Did you have to buy any special tools to do the job? My TIS says you need special tools to remove the fan. Any input on this job would be appreciated.

[johnlew]

Once in a very long while, I'll have to top off my '99 540 with a small amount of fluid. It had it's original radiator replaced at 105k miles.

[rph74]

From all the research that I've done, it appears that if you had an OEM Behr radiator installed in your car, then they last about 50k miles. Until BMW or aftermarket comes up with a better alternative, I would replace radiator and expansion tank every 50k. I replaced my radiator recently myself and got the radiator for $146 and expansion tank for $57 and did the replacement my self in less than two hours. BMW coolant is around $17/gallon. I would rather be safe with the radiator especially on a long trip--you could get stranded. Just my $0.02

Also, where did you buy the parts at those prices?

[rph74]

Once in a very long while, I'll have to top off my '99 540 with a small amount of fluid. It had it's original radiator replaced at 105k miles.

How many miles do you have on your radiator? How long have you had this problem also? I only add a small amount at a time also, and as stated above, it's every 2 months or so.

[johnlew]

How many miles do you have on your radiator? How long have you had this problem also? I only add a small amount at a time also, and as stated above, it's every 2 months or so.

About 15k. I've had the issue with the new radiator since getting it. Like I said though, it's a check coolant light after turning off the car, and very rarely. I'll top it off a bit and forget about it. It must be months in between because I'm surprised when I see it again. Just like, in this car, the check engine light comes on after running the A/C and goes out after turning it off for awhile. Never been figured out, just one of the quirks of the car. I don't worry about it.

[M.Wong]

I'd get the system pressure checked as soon as you can.

Mine went out on the E38 at 51K miles. Crevier BMW/MINI Parts offers a decent price, but you can expect them only to last 50-80K miles. Call Vaheh Bashikian and tell him Mark Wong suggested you call. He will give you a price and shipping costs.
(714) 835-3171 ext. 393

These were the prices a while back, I am guessing each has gone up just a bit.
17-11-1-702-969 RADIATOR $153.20
17-11-1-712-963 7-RIVET 2 $0.21 each
17-11-1-741-167 EXPAN. TANK $53.20
17-11-1-723-117 CAP $2.04
17-11-1-742-231 RADIATOR CAP $6.36
17-11-1-712-788 8-BLEEDER $2.56

I am pretty sure there are 540i sites like this:
E38 Radiator Replacement. (http://mywebpages.comcast.net/gsussman/cooling_system.htm) (I am guessing much of it is similar between the 740 and 540.)

Here is a possible alternative in the future:
Griffin aluminum radiators (http://www.vacmotorsports.com/cgi-bin/view_item.pl?cat=show&item_id=437) c/o VAC Motorsports. For now, until they come up with an alternative expansion tank, I just look at the radiators as wear items, like brake rotors. :( Fortunately, the parts are not terribly expensive now.

[E39spd]

I'd get the system pressure checked as soon as you can.

Mine went out on the E38 at 51K miles. Ours went on our 2000 E38 at 29K miles. :mad:

My 2001 E39 530i went through the water pump at 54k miles. :cry:

Both within a week of each other to boot and both out of waranty :madrazz:

I agree with M.Wong, have it pressure tested, this tells all and where it is leaking.

Good luck!

[M.Wong]

Ours went on our 2000 E38 at 29K miles. :mad:
My 2001 E39 530i went through the water pump at 54k miles. :cry:


29K miles??? Ouch!

Mine was under CPO, so it was $50. The water pump went 5K later, so it was another $50.

E39 is (hopefully) too new to have any problems soon. :)

[E39spd]

29K miles??? Ouch!

Mine was under CPO, so it was $50. The water pump went 5K later, so it was another $50.

E39 is (hopefully) too new to have any problems soon. :)Thanks, no CPO on the E38 or E39.

The E39 and E38 have both had the power steering hoses done (2 each).

E39 Crank Angle Sensor and Final Stage resistor too, I guess I have all the normal early failure items on my car.

E38 has had it's share of problems too!

Sorry to hijack the thread temporarily.

[rph74]

I'd get the system pressure checked as soon as you can.

Mine went out on the E38 at 51K miles. Crevier BMW/MINI Parts offers a decent price, but you can expect them only to last 50-80K miles. Call Vaheh Bashikian and tell him Mark Wong suggested you call. He will give you a price and shipping costs.
(714) 835-3171 ext. 393

These were the prices a while back, I am guessing each has gone up just a bit.
17-11-1-702-969 RADIATOR $153.20
17-11-1-712-963 7-RIVET 2 $0.21 each
17-11-1-741-167 EXPAN. TANK $53.20
17-11-1-723-117 CAP $2.04
17-11-1-742-231 RADIATOR CAP $6.36
17-11-1-712-788 8-BLEEDER $2.56

I am pretty sure there are 540i sites like this:
E38 Radiator Replacement. (http://mywebpages.comcast.net/gsussman/cooling_system.htm) (I am guessing much of it is similar between the 740 and 540.)

Here is a possible alternative in the future:
Griffin aluminum radiators (http://www.vacmotorsports.com/cgi-bin/view_item.pl?cat=show&item_id=437) c/o VAC Motorsports. For now, until they come up with an alternative expansion tank, I just look at the radiators as wear items, like brake rotors. :( Fortunately, the parts are not terribly expensive now.

Thank you very much Mark. I will use that info.