300e 1988 valve seals

hi i own 1988 300e with 110miles on it everything is in grate shape except headgasket but that dont bother me what bothers me is i have to clean ma spark plugs every 3 to 5 months they get oily and corosion then i get problems like hesitation from start lil rough indling but hard to notice so i take them out clean and its like new car its indling like the car is not even on and it goes like it got another

15hp boost when i open the cap on the egnine to put some oil i get steam coming out lil bit not alot no blue smoke coming from exaust cold or warm full throttle or idling so i think that only ma seals are worn what u guys think the car is in very good shape
Reply to
nawzy
Loading thread data ...

Yes, I concur it is the valve seals that are worn... causing your foul plug problem.

Reply to
Tiger

Tiger, and now for the umpteenth time because I've yet to read a clear answer to this. Seal replacement only or go the whole way......

cheers, guenter ... who's

Reply to
Guenter Scholz

Well, 110.000 miles is not a whole lot... so valve seals may just do it. You will know once you get to it... if you find the valve stem loose... you will have to do the whole job.

So a $500 job may turn into a $1500 job... If you are very good at head removal and installtion job, you can take it off and send it off to a machine shop... won't cost you much

You have to decide... are you the original owner? Did you or previous owner change oil regularly? Is the odometer correct? Seems kinda low for 88. If everything is no, then whole job is necessary.

Reply to
Tiger

Tiger, so are you saying that one can judge whether or not the valve stems need replacing (rather than just the seals) by 'wiggling' the stems? That would certainly be great..... my 300E has 145k miles, the plugs stay oily HC emission test show them to be just above acceptable limits, there are no visible oil leaks, no blue smoke etc, car burns about 1qut in 3000 miles BUT burns a lot more when driving high speed on the freeway for prolonged periods of time.

cheers, guenter

Reply to
Guenter Scholz

You can replace just the valve seals but it'll get you at best, a few monthes respite fropm the blue haze. Find a rebuildable head, cheap, git 'R redone properly, then install it yourself one weekend. If you can't find help to put a German car back together in KW you're just not trying. (I went to school there too.)

Reply to
Richard Sexton

here is where I become not sure what to do. What you say is often pointed out - however - the local dealership insists that the seals is all that is often needed (at around 200k km) ..... in view that a dealer typically wants to do more rather than less..... well it makes it kind of believable.

I addition, as I pointed out initially, I don't have blue smoke.... at least not as far as that I can see. Like I said, around town driving I need maybe a touch more than a liter between fills .... drive several hundred or so km at over 100km/hr I need a liter after.

..... so, again, what to do?

cheers

Reply to
Guenter Scholz

the valve guides can be checked for excessive wear before the seals are replaced . If excessive play exists then a head overhaul should be carried out as the new seals would prematurely wear. The material used to manufacture the guides was changed around 1991 due to premature wear. Earlier vehicles fitted 102 and 103 engines would wear guides around 100 000 miles while the later facelift models with modified valve guides would only require seals replaced at 100- 120,000 miles

Reply to
dratwal

bingo, many thanks. Now I understand as well the dealer 'advisor' take on this. seems that at 250k km I'm wayyyyy overdue for replacement of, apparently, the valve guies considering it's a '98 300e

cheers, guenter

Reply to
Guenter Scholz

Like Richard said...once you take out the seal, you can inspect the clearance between the valve guide and the valve stem... sometime the valve stem is loose and can be removed by your own finger.

As for few months on the valve seals... I am not so sure... but he is basically saying it is a bandaid job where it definitely will not last 3 years. You may or you may not luck out. (But you can try)

If you want something that last forever, valve job is the only way to go.

Now back to you... you said 1 qt per 3000 miles? That is normal... That should not oil out your plug... maybe you have a problem with your PVC system or too much fuel is burnt... but I highly doubt it is your valve seals.

Reply to
Tiger

Many thanks for the reply!! I think this is of interest to quite a few of us. good point re PVC and I will check it. Maybe I was being a bit optimistic re oil usage.... maybe more like 2 or 3 liters.

cheers, guenter

Reply to
Guenter Scholz

the car was owned by 65 yer old grandpa very ritch he is the original owner and has all the original paper work miles are original oil was changed regulary it was taken to the shop every time it was time to change oil but oil was bad if u ask me penzoil 10-30 juck when i bought it oil pressure would go to 0.5 in the summer so i drained the oil got mobil-1 and on top of that got 1 castrol systetic bottle the oil pressure went up to 1.3 in the summer when driven for long time so i fix that my father has been mechanic for 30 years he did vavle job by him selfe on mazda mpv he check ma car and he said that my engine is in grate shape that i don't have to wory obout valves only thing is seals are are obout 45% worn out and its making plugs oily lil bit he said he knows when valves are bad and mine aren't some one said i have to rebuil my head why when its in good shape i went and talk to another mechanic he said im 100% sure its seals cant be ur valves seals gave out bc of heat and oil eating it

Reply to
nawzy

If it is 2 quart per 3000 miles, then it is excessive.

Reply to
Tiger

The only tool your dad will need is a special spring compressor to do it . but before you buy it... see if he has something similar to it that he can get by... you can see the tool on internet... sold by lots of specialty shop.

Reply to
Tiger

Drive it till it becomes embarassing due to the smoke or expensive to keep adding oil, then fix it.

Reply to
Richard Sexton

Mercedes considers anything over 1 qt per 500 miles "acceptible".

Reply to
Richard Sexton

So, as the bard would say, here's the rub. As you know, the car needs to pass emission tests every 2 years. Lat time is was exactly on the max allowed HC emission of 60ppm .... after I got the cat 'red hot' and put new plugs in.

I imagine it's going to get worse.... so it's not poluting significantly in view that some other cars are allowed double or more of these emissions and still fall within allowed limits.... harumph.

cheers

Reply to
Guenter Scholz

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.