Author Topic: Thinner grade oil = huge blowby I think  (Read 6020 times)

April 28, 2008, 08:29:46 am

Laurentian

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Thinner grade oil = huge blowby I think
« on: April 28, 2008, 08:29:46 am »
Hi all,  car went to my machanic the other day and forgot to supply him with my favorite flavour 5-50 Mobil 1.
They put in some castrol type syn.
Got major blow by I think while driving to a customer's place 100k away.
Was a hot day with sustained fast driving.
1.6D with AWY tranny and 500,000 km,  original engine.
I filled the compete lane with billowing white smoke and overreved.
Took me a few seconds to figure out what was happening, shut off key
and pulled over.
Headgasket stil good, only 1.5 years old ( coolant fine )
Some oil seeped out my already leaking valve cover gasket big time.
No overheating at all.
Started up again after a minute or so and all fine except for burning
oil smell. Did not top-up oil since, probably burned off a half liter.
Will change out to my Mobil 1 5-50 tonight.
Very weird, think I came across this here before which prompted me to shut off key when I realzed what was happening.
Many thanks and opinions welcome please.

Hugh

Reply #1April 28, 2008, 11:26:15 am

jtanguay

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Thinner grade oil = huge blowby I think
« Reply #1 on: April 28, 2008, 11:26:15 am »
almost sounds like they overfilled your car with oil.


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Reply #2April 28, 2008, 12:09:24 pm

Vincent Waldon

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Thinner grade oil = huge blowby I think
« Reply #2 on: April 28, 2008, 12:09:24 pm »
I run Syntec 5W50 on my diesels with no issues... but there's a 5W30 and 10W30 version as well... in my mind anythingW30 is too thin ?
Vince

Edmonton, Alberta, Canada
2001 silver TDI Jetta Malone Stage 1.5 , 2001 blue TDI Jetta SBIII 216s Malone Stage 3, 1970 Bay Window bus

Gone but not forgotten: 1969/1971 Beetles, 1969/1974 Westies, 1979 Rabbit, 1986 TD Jetta, 1992 gas Jetta, 1994 TD Jetta

Reply #3April 28, 2008, 12:30:00 pm

Laurentian

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Thinner grade oil = huge blowby I think
« Reply #3 on: April 28, 2008, 12:30:00 pm »
Well, it basically was feeding itself on it's own oil.
I know some turbos have done that here before.
Oil level was fine when I got it back from Pascal.
It reved like crazy and when I let in the clutch it went into the red in a split second, foot off the pedal.
Kinda scary, took me a second or two to shut it off.
Glad it did turn off.
Thanks for replies.
Wingman is of the opinion that it did eat it,own oil.
Just want to firm that up  and see who it worked out for other board members and how long they were able to keep on running same engine.
Still works great by the way, took out the 1.9 block in my trunk
yesterday for added performance :lol:

Reply #4April 28, 2008, 05:14:23 pm

jtanguay

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Thinner grade oil = huge blowby I think
« Reply #4 on: April 28, 2008, 05:14:23 pm »
Quote from: "Vincent Waldon"
I run Syntec 5W50 on my diesels with no issues... but there's a 5W30 and 10W30 version as well... in my mind anythingW30 is too thin ?


yea w30 maybe for a break in on a tight motor??


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Reply #5May 06, 2008, 08:29:50 pm

Hermann

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Thinner grade oil = huge blowby I think
« Reply #5 on: May 06, 2008, 08:29:50 pm »
I have been running my old 89 on synth 5-20 (same as my truck) in winter and upping it to the same brand (Syntec) 10-30 in the summer. Never have had blow by issues. Leaks alittle more on the old pan in the summer but with 440 +kms what can youe expect? Never have had to add any oil between changes either - nothing significant anyway.

Just did the head gasket - barrels clean and smooth no ridge/burn/scoring etc. Nice and clean. Cam same way. Low weight synth oil has worked for me.

I would suggest someone overfilled your oil that day.
 :?
Failure to plan on your part does not constitute and emergency on mine.
_______________________________________
'89 Jetta (440k km and still gettin 53mpg!)
'99 Jetta TDI
'04 Golf  TDI (Wifey's car - Mom's Taxi)

Reply #6May 07, 2008, 04:37:02 pm

burn_your_money

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Thinner grade oil = huge blowby I think
« Reply #6 on: May 07, 2008, 04:37:02 pm »
500 000km with a AWY tranny, your rings are probably past due. I don't know if you have a tach or not, but "sustained fast driving" probably means your engine was reving past 3500.

If you don't have a cam splash gaurd, install one. I think if you take it slow, like 65mph, 110kph max you'll get some more time out of the engine. Just be  prepared to make an emergency stop with the brakes and clutch.

Thicker oil may help but I do think you should start with a dry compression test followed by a wet one to assess your rings
Tyler

Reply #7May 12, 2008, 04:45:12 pm

Laurentian

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Thinner grade oil = huge blowby I think
« Reply #7 on: May 12, 2008, 04:45:12 pm »
Thanks Tyler, you're right on the money.
Changed over to Mobil 5-50 last Friday night.
Same deal on way home but to a lesser degree.
Guess I was better prepared.
Really freaks out the tailgaiters!
I'll look into the cam splash guard.
Is that the mesh on the inside top of the valve
cover over the vent tube?
Nice to know that engine can keep on running.
Just bought a rotted out '92 with a 1.6D with a gas tranny at 350,000 km.
Maybe drop that one in until my 1.9 is built up.
Kind of like the simplicity of the 1.6D.
Thanks for the help and info guys!
Hugh