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Bottom end noises

Moss Motors
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Maryland, USA   USA
1978 MG MGB
Good morning, In late 2015, after just bought the B, I lost an oil hose and drove further that I should have. Long story short, winter of 2015 replaced the rod bearings and three main bearings without pulling the engine. Journals all seemed fine, no scratches. This past winter I pulled the engine and replaced the front and rear main bearings which I could not get to with the engine in, again, journals look fine. I pulled one connecting rod bearing to see what a years worth of driving had done to it and it look as good as the day I put it in. The car runs fine, plenty of pep. Problem is, if it sits for more than a couple of days, I get that lower end noise for a second until the oil gets to it, then it smooths right out. No noise if I drive it every day, (I know, I know, so drive it every day, what's the problem). Question is, what's the noise. Thanks in advance. Chas

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dipstick Avatar
dipstick Kenny Snyder
La Center, Washington, USA   USA
1941 Ford N-Series
1958 MG MGA 1500 Coupe "Rosie"
1970 MG MGB GT "Pat's GT"
1971 MG MGB "Gifted To Me"    & more
"The noise" is too vague. Rattle, thump, scrape, front, rear? Crankshaft rpm, camshaft/oil pump rpm; please be more specific.



Be safe out there.
Kenny

dickmoritz Avatar
dickmoritz Gold Member Dick Moritz
Philly 'burbs, PA, USA   USA
Sounds like oil drain-back out of the oil filter, and the rod bearinigs rattling until oil gets to them. If you're not currently running the Purolator PL20195 filter, try changing to that filter...

Dick



Errabundi Saepe, Semper Certi
(Often wrong, but always certain)

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Maryland, USA   USA
1978 MG MGB
Yes, Rattle is the word I would use. Just start up rpms. bottom end no doubt. So just so I understand, the filter is preventing oil from draining back into the engine without pressure? I'll change filters today. Thanks

Donthuis Avatar
Donthuis Don van Riet
Rijswijk, ZH, Netherlands   NLD
It is the reason I changed to the MAN 916/1 filter already many years ago. It has the best anti-flowback valve on this side of the ocean. You can check the anti-flowback valve quality of any brand by counting the number of seconds between zero and 75 lbs pressure upon cold start: my value is 2-3 seconds for any period of time in a month at least the B stands idle thumbs up

PS Rumbling noises I relate to the bottom end bearings only, rattling may also point to other parts in the engine



Edited 1 time(s). Last edit at 2017-04-10 10:12 AM by Donthuis.

RAY 67 TOURER Avatar
RAY 67 TOURER Ray Marloff
Fort Bragg, CA, USA   USA
1967 MG MGB "My Girl"
Yep, it's your oil filter's anti-drain back valve. A very common problem. X2 on the Mann 916/1 filter. RAY

rocannon Avatar
rocannon Platinum Member Frank L
Inconveniently located in the wilderness, Oklahoma, USA   USA
1967 MG MGB GT "GT From Hell"
1980 MG MGB "Restored By Photoshop Inc."
And ensure the spin-on filter base has a standpipe.



“Yes, another great idea destroyed by a simple set of facts."


“All of us at one time or another have had a sense of déjà vu, a feeling that this has happened before, that this has happened before, that this has happened before."



TANSTAAFL !

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riley1489 Avatar
riley1489 Gold Member Bruce H
Great White North, QC, Canada   CAN
1953 Jaguar XK120
1959 Riley 1.5 "King George"
1973 MG MGB
Based on the OP I suspect what Chas B is hearing/experiencing is worn big end bearings that rattle on start up.

Oil filter may be attributing to the rattle but the root cause is the damage caused by oil depravation to the bearings.

I hope for the OP I am wrong winking smiley

B



Check your ego Amigo!

dickmoritz Avatar
dickmoritz Gold Member Dick Moritz
Philly 'burbs, PA, USA   USA
OP says bearings are all new...

Dick



In reply to # 3486921 by riley1489 Based on the OP I suspect what Chas B is hearing/experiencing is worn big end bearings that rattle on start up.

Oil filter may be attributing to the rattle but the root cause is the damage caused by oil depravation to the bearings.

I hope for the OP I am wrong winking smiley

B



Errabundi Saepe, Semper Certi
(Often wrong, but always certain)

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riley1489 Avatar
riley1489 Gold Member Bruce H
Great White North, QC, Canada   CAN
1953 Jaguar XK120
1959 Riley 1.5 "King George"
1973 MG MGB
Dick,
Umm? Yes he did write that, thumbs up

he also wrote; "I lost an oil hose and drove further that I should have" .

My take on this, and perhaps a tad gloom & doom, but damage to the crankshaft journals, (out of round not visible 'scars') could have taken place,

Let's wait for the OP to change his oil filter type and report back.

I did write, " I hope for the OP I am wrong winking smiley"

B



Check your ego Amigo!

Maryland, USA   USA
1978 MG MGB
The Purolator PL20195 did the trick. Thanks all.

dickmoritz Avatar
dickmoritz Gold Member Dick Moritz
Philly 'burbs, PA, USA   USA
thumbs up

Dick

In reply to # 3494889 by Chas B The Purolator PL20195 did the trick. Thanks all.



Errabundi Saepe, Semper Certi
(Often wrong, but always certain)

riley1489 Avatar
riley1489 Gold Member Bruce H
Great White North, QC, Canada   CAN
1953 Jaguar XK120
1959 Riley 1.5 "King George"
1973 MG MGB
A happy ending,

Being wrong is so nice! grinning smiley

B



Check your ego Amigo!

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