bugsy1955

urgent: 68 Buick engine problem

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Hi Everyone,


Hoping to get some advice ASAP. My son brought his 68 LeSabre w/ a 350 engine to Florida while he attends college. Car has been running great until about a month ago. Had an acceleration problem that ended up being a need for new points and some adjustments. Seemed to purr nice and sweet after that. My son brought it into the shop due to some minor oil leaks. Had the intake manifold and valve cover gaskets replaced. Less than a hundred miles or so and I got a call saying the car suddenly lost acceleration and had some engine noise. He had pulled over immediately and did not drive any further. Had the car towed and found out had no oil in it. He had been checking the oil, so all the oil basically disappeared either suddenly or within a few days. Mechanic checked it out and found no leaks. Added oil, and purred again. Within a day of very local driving, there was excessive smoke coming from the dipstick. Oil was not burnt or discolored. I am in Pennsylvania, so  talking to my son and a passerby with classic car experience taking a look, we speculated that there was some pretty bad blowby occurring. The engine is original and low millage - @ 69,000 original miles. He replaced the original air cleaner a while ago and put on a chrome aftermarket air cleaner and filter.

 

Any ideas as to the issue?

Again the car had no problems at all until the points issue then the intake and valve cover gaskets.

I am in Pennsylvania and can't do much for him.

Mechanic said he was going to replace the PCV valve and see if that does anything.

Could the mechanic have screwed something up?

 

Any advise or suggestions will be greatly appreciated. He needs his car to drive between campuses and we are in one hell on a bind.

 

Thanks!
Kevin

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Can it have drunk all the oil via the PCV valve as a result of excessive crank case pressure? If so, maybe a compression test would be in order?

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I will have them check the compression in the morning. Thinking it could be the rings or valve seals, but the car was running perfect and not smoking at all prior and still has no smoke coming from the exhaust. 

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43 minutes ago, bugsy1955 said:

I will have them check the compression in the morning. Thinking it could be the rings or valve seals, but the car was running perfect and not smoking at all prior and still has no smoke coming from the exhaust. 

 

I suppose it what I speculated was true, there would be a very oily exhaust pipe.

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Have the intake manifold removed and reinstalled properly.  It sounds as if there is a leak between the lifter valley and one or more intake ports.  Carefully check the state of the intake gasket upon removal.  Reminds me of an episode of Fantomworks last year where a customer came in with the same very large oil consumption issue (~1 quart per 200 miles), but no outward leaks and no obvious smoke.  The car in that case was a small-block Corvette.

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Have the intake manifold removed and reinstalled properly.  It sounds as if there is a leak between the lifter valley and one or more intake ports.  Carefully check the state of the intake gasket upon removal.  Reminds me of an episode of Fantomworks last year where a customer came in with the same very large oil consumption issue (~1 quart per 200 miles), but no outward leaks and no obvious smoke.  The car in that case was a small-block Corvette.

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The intake manifold makes sense to me. The problem only started after the gaskets were replaced. 

Thanks for the responses!

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Just because the gaskets have been replaced does not mean that they were installed properly. Good luck solving your problem.

 

(o[]o)

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19 hours ago, bugsy1955 said:

Had the intake manifold and valve cover gaskets replaced. Less than a hundred miles or so and I got a call saying the car suddenly lost acceleration and had some engine noise. He had pulled over immediately and did not drive any further.

 

If the problem occurred so soon after the gaskets were replaced, what could have gone wrong when that was done? Would they have drained the oil to do that job and forgotten to refill it? I don't suppose you got an itemised invoice. If the oil blew out or leaked the engine bay or underneath would be covered in an oil slick.

 

Hopefully he stopped the engine soon enough to prevent major damage but it sounds like an engine disassembly is in the next holidays, if not sooner?

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Nothing more frustrating than being 1200 miles away from a car having issues.

So, I spoke to this mechanic guy that my son is using. Advised him of the suspicion that the intake manifold gasket may not have seated correctly. He felt he had a handle on the problem as being related to the PCV and vacuum lines. Said pressure was released and car was running perfect. 

 

WELL, son picked it up and said was driving and sounding fine. A little oil dripping and smoke coming from under car but we figured it was just some oil that probably spilled when they were working on her. And the oil pan drain plug is having issues so figured would drip a few drops now and then. No smoke coming from dip stick. No apparent blowby. 

 

Next thing I know, my son facetimes me as the oil is rapidly dripping when the car is running. Asked him to try and trace the oil leak but the most he could see is it pouring down in front of the oil pan. 

 

Again no issues or leaks prior to recent work. Most recent is the valve cover and intake manifold gaskets. Recent prior was new radiator, points, distributor cap, and timing. Son said the mechanic also put a gasket on dipstick.

 

Any and all help is appreciated. For those that may be saying why aren't I fixing myself, I am 1200 miles away. Those that say better take that car to another mechanic, I am already there and will see what the current guy says tomorrow,

 

Thanks!

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I agree with the others..... Intake manifold gasket. I had a Mustang V6 given to me because the guy thought it had a blown head gasket and ran terrible. It was losing oil and water. As I took it apart I found a distorted / cracked intake gasket. I took a chance and went back together only replacing the intake gaskets. Car ran great for the next 25,000 miles until I went to a different vehicle.

Edited by fordrodsteven (see edit history)

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Hard to work on these things via the forum, but Mr. Em Tee seemed on target with one of the side intake gaskets being improperly installed. As he mentioned, in that case, oil is sucked out of the valley into one or more intake ports and is burned. Your latest post however, indicates that there is an EXTERNAL oil leak at the front of the engine. If indeed related to the previous work done, it would be the end gasket at the front of the intake manifold slipped when the intake was installed, or one of the valve covers may have a serious leak at the front. Either way, the source of the external leak should be fairly easy to locate.

 Something else that concerns me is your references to oil/fumes coming out of the dipstick, an aftermarket air cleaner being installed, and mention by the mechanic of PVC/vacuum hose issues and installing a new dipstick tube gasket. If the PVC system was plugged up ( when installing an aftermarket air cleaner?) for any reason, the engine will blow oil out the dipstick tube. It's possible for the crankcase pressure to cause other seals to blow as well, such as a timing cover seal. Good luck, and let us know what is found.

Edited by 31 Caddy (see edit history)

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Thanks 31 Caddy. I am sure nothing was plugged and the air cleaner has been on there for over 2 years. The gasket for the dipstick actually is a makeshift plug that the mechanic put in the dipstick tube made in response to a warn gasket on the dipstick. I am wondering if plugging the dipstick tube to the point of needing to remove it to check the oil level,because it wipes the dipstick clean, could have anything to do with the issues.

 

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Next time you run the engine remove the oil filler cap while it is running. When the cap is off it should not be blowing pressure out of the filler area while the engine is running. If it is first check to see if  the PCV valve is working by removing the PCV valve with engine running and verify that there is a decent amount of vacuum being drawn at the opening of the PCV valve. there are some old flow testers for PCV systems but few people have them and you can thumb check a similar model that is not having the issue. Engines that have heavier blow by past the rings will slowly coat the vacuum passage way shut to the point that there is little or no PCV action. Also remember the PCV system has a hose usually 3/8" or so inside diameter that comes from filtered air at the air cleaner to allow the vapors pulled by the PCV system to be replaced without allowing a high vacuum applied to the crankcase thus sucking dirt and other impurities into the engine from poor sealing areas. When blow by on engines become excessive the PCV system cannot flow enough and oil will be deposited in the air cleaner through the breather hose.  I have seen people remove these lines and sometimes plug them. If the PCV valve is removed from the valve cover, the engine is running and the filler cap area has a vacuum that draws on your hand when placed over  the opening I would be very suspicious of an intake sealing problem.

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8 hours ago, c49er said:

Where is the oil sending unit located?

Oil sending unit is located down near the oil filter (lower front corner on passenger side).

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I had a problem leaking oil on 350 engine--dipstick  casing on the end was not fitting in hole on engine =resulting in leaking out as the engine revved higher   wouldn't notice it on idle but when driving would blow by seat of dipstick   good luck   also maybe piece of old manifold gasket got pushed into manifold opening somewhere 

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Hello All!

Sorry been out of touch as have been swamped with work. Brought the Lesabre back to the mechanic and after an extended period of time, he finally seemed to fix her up. He replaced a number of seals and gaskets. The car ran great, no oil disappearing, no blow by, and purred. Well, the car has been parked in my garage for the past month or so. My son drove up to my house about 90 miles and 5 miles away, the oil light came on. Seemed their was not much oil pressure. 

 

Any ideas?

 

Anyone know of a GOOD mechanic by Palm Bay Florida? I am only there a few days every other month or so, thus not much time to fool around with it myself. Figured I would pick up a gauge and check the oil pressure when I get down there in a few weeks.

 

Thanks!
Kevin

 

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How did the garage floor look when your son pulled it out into the driveway after sitting?

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