Eagle 258 with oil soaked air cleaner
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Forum Name: AMC 6 Cylinder Engine Repair and Modifications
Forum Description: AMC-made I-6 engine mechanical, ignition and fuel from basic repair to high-perf modifications
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Topic: Eagle 258 with oil soaked air cleaner
Posted By: MIPS
Subject: Eagle 258 with oil soaked air cleaner
Date Posted: Mar/14/2019 at 8:04pm
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I noticed this was an issue when I first bought the car. The air cleaner was contaminated, the PCV breather filter element was soaked and the interior of the air cleaner down to the lowest corner of the snorkel had oil in it. It wasn't so much that I had it "gushing" out but enough for it to pool in the cleaner. Removed and tested the PCV valve and found it to occasionally get stuck partially open, so it was replaced. Cleaned out the air cleaner housing, squeegeed out the breather filter and ran it for another week and a half and found the breather again had oil in it and oil was developing around the cleaner again. Attached a vacuum gauge to the PCV valve and found 18 InHg of vacuum, which should be plenty. Disconnected the PCV breather hose and tried from that port with the engine at a warm idle and found it could at best pull the crankcase down to 1 InHg of vacuum, rising to a positive 1PSI of blow-by if revved, which in my head sounds okay IF the vacuum was higher, but I've never worked on an engine like this. The engine has an aluminum aftermarket valve cover with oil baffles on the PCV inlet and outlet. I am aware there is currently a small amount of oil leaking from the front right corner of the cover gasket but that can't explain the massive loss of vacuum. The rest of the gasket seems good and there are no other signs of oil leaks. Engine and carb is otherwise stock. |
Replies:
Posted By: Trader
Date Posted: Mar/14/2019 at 9:37pm
| Time to do a cylinder compression test. A bad intake valve will loose vacuum. Bad rings will loose vacuum and push oil or burn it. |
Posted By: partsguy
Date Posted: Mar/14/2019 at 10:22pm
| does the engine have alot of blow by ? |
Posted By: MIPS
Date Posted: Mar/14/2019 at 10:44pm
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I only have the tools to measure vacuum and pressure and do not have the components for even a DIY manometer but at the least there has been no visible signs of a very serious blow-by condition or excessive oil consumption. The plugs are being swapped this weekend due to age. I can check the cylinder compression then and the status of the old plugs. |
Posted By: partsguy
Date Posted: Mar/14/2019 at 11:02pm
| as trader suggested a compression test will show alot, |
Posted By: pacerman
Date Posted: Mar/15/2019 at 4:15pm
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Make sure you have a working PCV valve and that the PCV valve circuit is sound and connected properly. Didn't Linda Rondstadt have a hit song about that problem? Blow By You. Joe ------------- Happiness is making something out of nothing. |
Posted By: tomj
Date Posted: Mar/15/2019 at 9:55pm
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this is too obvious and oyu sound alert, but it's not over-full of oil? that's odd... trader's suggestion will tell a lot. but even with a fair amount of blowby, say, old engine, that might chug fumes out the filler cap but liquid oil? neva herda dat. you can run with a plugged-off PCV for testing. no harm will be done in a week or two even, and it might help separate symptoms. with the engine stopped, you can manually check for a sealed crankcase; put a hose on the PCV and blow into it like inflating a balloon. it should hold the pressure reasonably well with your finger on the end of the hose. or use a Mighty-Vac, but probably a lot of pumps (it's a large volume). divide and conquer. ------------- 1960 Rambler Super two-door wagon, OHV auto 1961 Roadster American, 195.6 OHV, T5 http://www.ramblerLore.com |
Posted By: purple72Gremlin
Date Posted: Mar/16/2019 at 2:20am
| Been my experience that when the air cleaner has oil in it...the rings are stuck or worn out. |
Posted By: Greyhounds_AMX
Date Posted: Mar/16/2019 at 7:21am
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I'd check the compression as it might give some clues. You could also consider cleaning the ring grooves a bit. The 1st gen Saturns had an oil consumption issue due to the ring grooves building up crud so the factory had a procedure for cleaning them that worked pretty good: Procedure - 1 Internal Engine Cleaning 1. Warm up to normal operating temperature. Important In order for the cleaner to be effective, the engine must be warm. 2. Disconnect negative battery cable. 3. Remove spark plugs. 4. Rotate engine crankshaft until notch in crank pulley is at 3 o'clock (90° after top dead center) position. This will position all of the pistons midway in their bores. 5. Pour 3 ounces of GM Piston and Ring Cleaner (P/N 12378549 12 ounce bottle) into each cylinder through the spark plug hole. 6. Cover the cylinder head and spark plug holes to prevent debris from getting into the combustion chamber and to prevent excess evaporation of the cleaner. 7. Allow the engine cleaner to soak for a minimum of 2 hours. Notice After the minimum 2-hour soak, there may be some cleaner left in the combustion chambers. Do not start the engine until all of the cleaner has been removed from the combustion chamber or severe engine damage may occur. 8. After the minimum 2-hour soak, remove the remaining cleaner from the combustion chambers by placing shop towels over all of the spark plug holes and cranking the engine through a few revolutions. 9. Install the spark plugs and spark plug wires. 10. Start the engine and run only enough to reach normal operating temperature. 11. Drain the engine oil and remove oil filter. 12. Install new oil filter (P/N 21000872). Important *Mobil® 1 Synthetic 5W-30 or 10W-30 engine oil is to be used during the initial oil change interval following this procedure. Mobil® 1 Synthetic oil has excellent engine cleaning properties that will aid in removing deposits that were loosened and softened during this procedure. *We believe this source and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such items which may be available from other sources. 13. Install 4 quarts (3.8 L) of Mobil® 1 Synthetic 5W-30 or 10W-30 engine oil. 14. Return vehicle to customer. 15. After 1500-3000 miles of operation, have the customer return for next oil change. 16. Drain engine oil and remove oil filter. 17. Install new oil filter (P/N 21000872) 18. Install 4 quarts (3.8 L) of engine oil meeting Saturn specifications. 19. Refer to Oil Consumption Test and perform steps 4 through 8. ------------- 1968 AMX 390 w/T5 |
Posted By: First_Gear
Date Posted: Mar/16/2019 at 12:03pm
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If you find poor compression. Rent or buy a leakdown tester. It is an invaluable tool. Used correctly you can determine if its the rings or the intake or exhaust valve.
PS: to use the tool you must have an air compressor
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Posted By: MIPS
Date Posted: Mar/16/2019 at 6:02pm
Did the plugs and the test today. Here's the gritty on the old plugs. All of the plugs look good on one side and stained on the other. They were all also horribly gapped. As for cylinder compression CONSIDER THE FOLLOWING BEFORE YOU READ THE NUMBERS: It appears my 14mm fitting is not deep enough to securely seat in the plug hole. I can barely get two or so threads in with the O-ring removed but as a result all the readings will be lower than normal due to leaking around the fitting.  1 - 150psi (easy reach, could screw the tester in a bit more with pliers) 2 - 130psi 3 - 135psi 4 - 140psi 5 - 135psi 6 - Unable to get the tester in So taking the above while aware the tool was not installed properly it looks pretty uniform between cylinders and reasonably good
No that's a valid question to ask. When I bought the car six months ago the oil level was sitting above the FULL line (and over the "FULL" text on the dipstick). Today it's still above the FULL line but it's now down to about 1/4" above the line.
I plugged the PCV ports and used a piece of radiator hose to blow air in via the oil cap. It's holding pressure pretty good, though it's clearly leaked oil since I wiped the manifold down yesterday. |
this is too obvious and oyu sound alert, but it's not over-full of oil?Posted By: FSJunkie
Date Posted: Mar/18/2019 at 10:57pm
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Compression looks good. A lot of Eagles had a PCV shutoff solenoid that the computer used to shut off the PCV flow on some occasions. A problem may exist with that solenoid. There may be no baffle under the air inlet hose at the back of the valve cover to prevent oil from splashing up off the rocker arms and entering the hose. Lots of full throttle use will push more oil into the air cleaner. PCV cannot work at full throttle. ------------- 1955 Packard 1966 Marlin 1972 Wagoneer 1973 Ambassador 1977 Hornet 1982 Concord D/L 1984 Eagle Limited |
Posted By: tyrodtom
Date Posted: Mar/19/2019 at 8:54am
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There's supposed to be various adapters on that compression gauge fitting with a O-ring on it , or tapered for the different spark plug types. You seemed to have got it to work OK on most of the plugs without the adapters. Plus those plugs are in gaped pretty haphazard , especially that one in the middle with the ground strap not in alignment with the electrode.
------------- 66 American SW, 66 American 2dr, 82 J10, 70 Hornet, Pound, Va. |
Posted By: MIPS
Date Posted: Mar/19/2019 at 6:55pm
My eagle doesn't appear to have a solenoid on the PCV. Vacuum seems to come direct from the base of the carb to the PCV where it tees off at the PCV valve to the charcoal canister and the valve cover. The other side goes straight to the breather in the air cleaner. The diagram for the CeC does not indicate any computer control on the PCV either, so it's not electronic at least.  (diagram above confirmed correct, excluding Divert and Upstream solenoids, as my Eagle shipped without the pulse air system) Someone else suggested I verify an oil baffle is in the aftermarket valve cover and at the least I can look down both openings and there's a metal plate blocking a direct view at the valves but I have not removed the valve cover to confirm a baffle assembly is in there. That requires a tube of Right Stuff. For the sake of it I've removed the old breather filter element and replaced it with a clean element. Another thing I didn't think of was the old filter was so badly soaked it was inhibiting enough air passing through it. I'll leave it in there for another week or so and see if the problem returns. |
Posted By: Trader
Date Posted: Mar/23/2019 at 5:52am
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While look for the baffle, if possible, look for blocked oil returns and oil accumulation on top of the head. Oil does not usually just get sucked out the top of an engine. The crankcase is either getting pressurized or the oil level/aerated oil is high enough to get caught by the PVC circuit. This aftermarket cover begs the question, is the "baffle" catching/pooling oil from the rockers and is there a path back to the breather from there?
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Posted By: 1982AMCConcord
Date Posted: Mar/23/2019 at 1:11pm
| I had this on my 258... eventually it got worse... I kept cleaning it out... then one day it started oozing white foaming goo into the air filter housing.... and that ended up being a blown head gasket... then I rebuilt the whole engine at that point... |
Posted By: FSJunkie
Date Posted: Mar/25/2019 at 1:29am
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The oil return drain holes in my 258 were very plugged up with a combination of sludge and silicone sealer from dozens of valve cover gasket jobs. It was all down around the lifters. I literally had to dig it out with a spoon and then I had the entire block vatted. They don't plug up with sludge like that if you use good oil and maintain the engine properly, but few 258's have had proper maintenance over their entire lives. Most of the Eagles still on the road today were used as $200 winter beaters at one point in their life, and one point is enough to do it. Or the "it leaks so much oil that I just keep adding it and changing the filter" mentality. That will plug them up too. ------------- 1955 Packard 1966 Marlin 1972 Wagoneer 1973 Ambassador 1977 Hornet 1982 Concord D/L 1984 Eagle Limited |
Posted By: MIPS
Date Posted: Mar/26/2019 at 9:02pm
| I have no idea what the previous owner used for oil in this. Typically I've gone for Penzoil High Mileage as I exclusively used it in my previous car until I retired it. I was planning on replacing the filter and oil in the Eagle pretty quickly so I knew exactly what was in the block. |
Posted By: FSJunkie
Date Posted: Mar/28/2019 at 1:57am
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We've all heard the Pennzoil and Quaker State sludge horror stories, but sludge comes from neglect, age, and wear. All the engines I've dealt with that had serious sludge problems had a known past of poor maintenance and use. Short trips, infrequent changes, overheating, and valve cover leaks. Those will all gum up an engine. ------------- 1955 Packard 1966 Marlin 1972 Wagoneer 1973 Ambassador 1977 Hornet 1982 Concord D/L 1984 Eagle Limited |
Posted By: tomj
Date Posted: Mar/28/2019 at 9:14pm
yup. i don't think you can buy "bad" oil today, certainly not any even crappy brand name. the lowest house-brand oil from autozone or CVS will be as good or better than average oil from the 60's. it's very straightforward -- old engines need to be rebuilt. "low miles" only matters if it's also "low years". 40 years old is ancient, 5 times design life. when cars get to be 10, 15 years old it's "give it to the kid" handmedowns and maintenance usually ends there, then it ends up behind a barn, until we pull em out and revive them. the maintenance that was deferred in 1980 has certainly come due in 2019! ------------- 1960 Rambler Super two-door wagon, OHV auto 1961 Roadster American, 195.6 OHV, T5 http://www.ramblerLore.com |
Posted By: MIPS
Date Posted: Mar/29/2019 at 6:14pm
| Replaced the valve cover gasket and found the PCV breather now builds a vacuum when plugged with a thumb and does so even harder with a hard engine rev. I guess it really was just a really badly leaking valve cover gasket. |
Posted By: FSJunkie
Date Posted: Mar/30/2019 at 1:25am
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Yeah, that'll do it. The crankcase needs to seal for the PCV to work. Otherwise it might as well not be there at all. It's very bad for the engine to run with a leaking valve cover. Some of the problems it causes other than making a mess of the engine and air cleaner: 1. Reduced PCV effectiveness lets the crankcase fill with blow-by rather than sucking it out and replacing it with clean air. The blow-by turns the oil acidic or forms sludge. 2. The leaking gasket creates a direct path for dirty outside air to be drawn into the crankcase rather than only clean, filtered air from the breather. This grit goes to work on the rings and cylinder walls. How big of a difference does it make? Tons. My first AMC six had so much cylinder wear at 116,000 miles that it needed a .040" overbore at that time. My second AMC six had so little cylinder wear at 167,000 miles that it's just got a hone and new rings at that time and is still running as strong as ever to this day on it's original bore and pistons. The difference? Valve cover sealing and breather filter maintenance. ------------- 1955 Packard 1966 Marlin 1972 Wagoneer 1973 Ambassador 1977 Hornet 1982 Concord D/L 1984 Eagle Limited |
Posted By: MIPS
Date Posted: Apr/06/2019 at 8:14pm
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Nah, it's still doing it. So after the last PCV filter change I wiped down the air cleaner and removed all residual oil, except the oil contaminated filter because I did not want to ruin another filter if I was possibly wrong. Two weeks later:   It's not the PCV. There's no oil around the breather filter and the filter is still clean. The oil slick indicates that it is coming from somewhere within the clean side of the filter element. I'd immediately blame the filter itself but that's an awful lot of oil. The vehicle does not have issues with backfiring, nor did the compression test indicate an obvious stuck intake valve. There is also no excessive oil consumption either. |
Posted By: Greyhounds_AMX
Date Posted: Apr/07/2019 at 10:10am
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I believe the oil film you see in the pics came out of the old oil soaked air filter. Everything else looks good, so I expect if you swap in a new filter that should wrap this up. ------------- 1968 AMX 390 w/T5 |
Posted By: MIPS
Date Posted: Apr/07/2019 at 11:22pm
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Okay, I'll swap out the cleaner element and replace the breather element as well. For those wondering if I'm just buying new PCV filters each time, no. I'm cutting small rectangular chunks from a roll of white open-cell foam padding and repacking the original FRAM filter cartridge. 
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Posted By: FSJunkie
Date Posted: Apr/08/2019 at 1:07am
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Yeah that's probably just from the soaked filter. Make sure the inner vacuum door of the air cleaner is open any time the engine is running and that the vacuum delay valve holds it open for a while even after the engine is shut off. Make sure the outer vacuum door is open after the engine is fully warmed up. ------------- 1955 Packard 1966 Marlin 1972 Wagoneer 1973 Ambassador 1977 Hornet 1982 Concord D/L 1984 Eagle Limited |
Posted By: MIPS
Date Posted: Apr/08/2019 at 9:24am
| When I was doing maintenance yesterday I replaced all the vacuum lines for both doors and verified the TAC valve and both actuators were working. |