...........you OK today???

I don't ever remember saying this.....

What in the world is a forum for if people can't talk about problems or ask questions anyway????? How else do you learn about stuff???

If the level falls below the low level switch when doing this coolant burb, are you supposed to add fluid to a certain level?

Thanks

Don't mind him. He's normally quite helpful . See my post, #76, above.

If the level falls below the low level switch, then add coolant to keep it up to the full mark. It may continue to drop as the air starts to slowly work its way out of the system.

If, after 15 minutes, the coolant does not stabilize in the tank, and continues to go down further, then, add coolant, and continue to run the engine until the level stabilizes.

Thanks

Hello,

Tried the coolant air purge. No change. I dropped the car off Monday to get looked at. He strongly believes it is either a cracked head or bad gasket. As people have said, it is hard to tell until you remove the head.

I was wondering if anyone knew where the most common spot for the aluminum head to crack?

What is the part number for the replacement / updated head? I always here 17?

Scott

The common weak spot is in the #4 and #5 combustion surfaces. The visible cracks are between the intake and exhaust seats. By the time you see those cracks the runners have cracked through to the water jackets.

14, 17, 22, etc. are 7th adn 8th digits in the visible head casting number. The part number for the latest head (22) is 603 010 96 20. If you buy a new head from a reputable source you won't have to specify the casting or part number. They only sell the latest heads are available. The numbers only matter when buying a used head or a new head from an unproven source. And there are folks who've done well replacing with a used 14 head.

Sixto
95 S420
87 300SDL

17 is the earliest 'good' head. It has problems with oil passages that were corrected in later heads but cracking is not known to be a problem.

Sixto
95 S420
87 300SDL

17 and 22 are updated heads. 17 came on the '90/'91 350SDL I believe. 22 I suppose on mid '90s vehicles.

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

Actually I think they used 17s in all US 603.970s. Later heads were not original equipment on any US-spec engine.

Sixto
95 S420
87 300SDL

EPC shows the same original part number from 90 through 95. There's a part number between the 86-87 head and the 90-95 head.

Sixto
95 S420
87 300SDL

Ah interesting.

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

Sixto wouldn't a "22" head have the part number of 603 010 22 20?
Then you would have:
603 010 18 20
603 010 17 20
603 010 15 20
603 010 14 20
?

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

One would think but the head part numbers are:

603 010 35 20 = 14, original 86-87

603 010 42 20

603 010 56 20 = 17, original 90-95

603 010 71 20

603 010 72 20

603 010 96 20 = 22

Go figure.

Sixto
95 S420
87 300SDL

Something is not right.

Some of the 14 heads certainly had part number 603 010 14 20

My 15 head has part number 603 010 15 20.

brian, dont drop this thing off some where....
this fellow cant tell you anything... get you some doctors gloves
and take the head off....

then take it to a good machine shop they will preasure test it..

and if it is cracked they can weld it... I just had my head redone
for 250 bucks.... but it might cost 350 with a weld...


now a days they preasure test and do whats called magna flux...

and they can even weld aluminum ....so dont sweat it...

anyway a junk yard head with a burnt valve probably 100 bucks..