Loud noise from overhead...suddenly

[87LtdT]

Below is my engine info...have driven the car very little over the past 6 years...total of 700 miles. Had not changed oil during that time...an oversight. The car resides in a heated and cooled concrete floored pole barn...temp extremes are 40F to 74F.

So I take it for an infrequent drive 3 weeks ago. 3 mile gentle drive to the interstate on-ramp...hot rod down the on-ramp...and the remainder of the 20 mile interstate and in town drive was very gentle. Coming home on Interstate I decide to hot rod from 60-80 or so. Floored it and it did not downshift ??? and didn't feel like I had much power...might be wrong since no downshift involved. Coasted back to 60 and did it again...with same result. 3 miles later as I exited via the off-ramp I noticed a lot more engine related noise. Drove the final 3 miles home very gently. Got home, and due to my wife breaking her hand while I was out, I didn't work much on the car.

Noticed milky substance on the oil fill tube and on the visible surfaces under the valve cover...that's when I realised it had been 6 years since oil change!! Drained the oil and it was "milky"...but not too bad. Removed plugs and they were sooty but otherwise OK. Compression test revealed low of 188 and high of 202psi. I put in new plugs, new oil with a quart of Marvel Mystery Oil, and filter.

Restarted and there is a lot of lifter, or overhead noise...pretty loud. Not positive where it's coming from...have Caspers "red light" cam sensor cap and thought I'd read they were a source of noise...wasn't noisy before though.

So looking for ideas regarding the cause...it seemed to happen during the 2 WOT blups on the way home. Suddenly.

Thanks, Bob

 

[ryan george]

Sounds like you blew a head gasket. Someone more knowledgeable will chime in, but milky oil is not good. I wouldn't start it again. Casper's cap should have nothing to do with it.

 

[Pronto]

Driving around on old gas by any chance?

 

[87LtdT]

Driving around on old gas by any chance?

No not too old...drive it into town once in a while. But certainly not "Fresh" gas.

 

[TurboDave]

Well the milky oil indicated you've blown the headgasket and got coolant/water into the oil. If the car has anything other than straight water in the coolant system, like anti-freeze, you've also likely ruined a bunch of bearings. Hence the noise you're hearing.

 

[87LtdT]

Driving around on old gas by any chance?

No not too old...drive it into town once in a while. But certainly not "Fresh" gas.

Sounds like you blew a head gasket. Someone more knowledgeable will chime in, but milky oil is not good. I wouldn't start it again. Casper's cap should have nothing to do with it.

I thought the same but the compression numbers appear good...and the sound is more metallic sounding. Hard to describe.

 

[TurboDave]

Well the milky oil indicated you've blown the headgasket and got coolant/water into the oil. If the car has anything other than straight water in the coolant system, like anti-freeze, you've also likely ruined a bunch of bearings. Hence the noise you're hearing.

 

[Rafs-T-Type]

How far is town? Does the car get to proper operating Temp by the time you get to town? 6 years of shorts drives can pull a lot of moisture in.

 

[87LtdT]

How far is town? Does the car get to proper operating Temp by the time you get to town? 6 years of shorts drives can pull a lot of moisture in.

7 miles total...3 country roads and then 4 on interstate...then a little within town before driving home. I think the same as you ... ie that is the source of the milkiness. If head gasket is blown...would the compression numbers be so good??

thanks

 

[87LtdT]

How far is town? Does the car get to proper operating Temp by the time you get to town? 6 years of shorts drives can pull a lot of moisture in.

7 miles total...3 country roads and then 4 on interstate...then a little within town before driving home. I think the same as you ... ie that is the source of the milkiness. If head gasket is blown...would the compression numbers be so good??

thanks

Well the milky oil indicated you've blown the headgasket and got coolant/water into the oil. If the car has anything other than straight water in the coolant system, like anti-freeze, you've also likely ruined a bunch of bearings. Hence the noise you're hearing.

Only water with a water-wetter...RMI 25 I think.

 

[87LtdT]

How far is town? Does the car get to proper operating Temp by the time you get to town? 6 years of shorts drives can pull a lot of moisture in.

7 miles total...3 country roads and then 4 on interstate...then a little within town before driving home. I think the same as you ... ie that is the source of the milkiness. If head gasket is blown...would the compression numbers be so good??

thanks

Well the milky oil indicated you've blown the headgasket and got coolant/water into the oil. If the car has anything other than straight water in the coolant system, like anti-freeze, you've also likely ruined a bunch of bearings. Hence the noise you're hearing.

Only water with a water-wetter...RMI 25 I think. No anti-freeze.

 

[TURBOELKY]

Might only leak when engine is up to temp.

 

[gsgnnut]

pressure test cooling system to determine if a head gasket failed first. The noise is likely oil starvation to lifter valley among other places. Oil and water when heated and mixed make a viscous goo that is a bitch to flush out. I had a boat that had a riser failure that filled the crankcase with sea water. Oil turned to glue. Took 3 or 4 oil changes to flush all traces of water out. Change the oil and filter a couple times and gently run it each time to heat and circulate the contamination down to the pan. If you have no head gasket leak each oil change will get noticeably cleaner and the motor will run better and should quiet down. My boat motor survived certain death by that drowning but it later ate a spark plug and washed down a cylinder before I could get to port for repairs and she still ran but smoked like a fiend after that . Also, water in oil in the crankcase for long periods of time eats up crank bearings. I blew up 455 that way. needless to say I never put off oil changes on vehicle, especially those in storage.

 

[87LtdT]

Might only leak when engine is up to temp.

Thanks...Elky

 

[earlbrown]

check for a broken rocker shaft too.


I can't explain this for the life of me but for some reason losing it can fog a crank case with water. Years ago I bent two pushrods on my GN and drove home on 4 cylinders. The engine was milkshaked. Replacing the pushrods fixed it. Years later I broke a rocker shaft... same thing.

A couple years ago I broke a valve spring on my boats 454. Drove back to the ramp on 7 and, for some damn reason, milkshaked the oil again. New valve springs stopped it.


If your noise is a top end rattle, you might have gotten lucky.