Oil leak

zonian91 · 02-22-2015, 04:30 AM

My son just bought his 1st car today. A beautiful 1987 Supra (non turbo). The car drove amazingly great, but after we got done eating dinner we noticed an oil leak. We checked the oil before leaving and the level was full. Any info on common oil leak problems with this model?

zonian91 · 02-22-2015, 05:04 AM

A little help please!

btwilson86 · 02-22-2015, 03:46 PM

I'd check first to see if you can narrow down what part of the engine you see the leaking at. If I couldn't determine that, then I look at the oil drain plug and oil filter, I've found those loose on a couple cars I've had. If that looks okay, then there are a couple common oil leaks on these Supras. Check on the exhaust side of the engine just below the distributor. Lots of oil there? Likely a bad o-ring around the distributor shaft. Remove distributor, replace o-ring, reinstall distributor, and reset ignition timing. Another common oil leak is the no. 3 cylinder head cover. This is the piece that runs the length of the engine between the valve covers, that the spark plug wires clip into. This cover doubles as a gasket for 4 oil passages across the cylinder head. When these leak, which they almost always do, you usually find lots of oil on your spark plug wires, and it can get bad enough to cause misfires if left unchecked. You likely won't see the oil until you pull a spark plug boot out and fling oil everywhere. This piece is fairly straightforward to replace after removing the throttle body, intake pipe, and spark plug wires. Remove it by removing the 4 oil plugs holding it in, they use a 14mm hex key or Allen wrench. If it was leaking, you should replace your spark plug wires and possibly spark plugs as well. Also, since you're already torn down this far, its not a bad idea to replace the valve cover gaskets as well, as they tend to leak a little oil with age.

zonian91 · 02-22-2015, 07:29 PM

Thanks a lot for responding and the advise. I'll check that out ASAP.

zonian91 · 02-23-2015, 03:09 AM

Looks like you were right. There is a lot of oil built up underneath the distributor and there was also a lot of oil around the spark plug wires on the head. I sprayed some purple power on it to clean it off before tearing it down, but now the car is idling rough! It was running perfect before?

btwilson86 · 02-23-2015, 01:53 PM

If the oil is around the spark plug wires, it seeps into the wire making a poor connection to the spark plug causing the spark to short at the cylinder head and not travel to the plug, resulting in misfires and rough running. I'm not sure how a degreaser could cause a rough idle, unless a lot of it collected in one spot and is basically doing the same thing the oil was

02-22-2015, 04:30 AM	#1
zonian91 Stock Join Date: Feb 2015 Location: Newport News, VA Posts: 8	Oil leak My son just bought his 1st car today. A beautiful 1987 Supra (non turbo). The car drove amazingly great, but after we got done eating dinner we noticed an oil leak. We checked the oil before leaving and the level was full. Any info on common oil leak problems with this model?

02-22-2015, 03:46 PM	#3
btwilson86 Super Moderator Join Date: May 2007 Location: Billings, Montana Posts: 1,034	I'd check first to see if you can narrow down what part of the engine you see the leaking at. If I couldn't determine that, then I look at the oil drain plug and oil filter, I've found those loose on a couple cars I've had. If that looks okay, then there are a couple common oil leaks on these Supras. Check on the exhaust side of the engine just below the distributor. Lots of oil there? Likely a bad o-ring around the distributor shaft. Remove distributor, replace o-ring, reinstall distributor, and reset ignition timing. Another common oil leak is the no. 3 cylinder head cover. This is the piece that runs the length of the engine between the valve covers, that the spark plug wires clip into. This cover doubles as a gasket for 4 oil passages across the cylinder head. When these leak, which they almost always do, you usually find lots of oil on your spark plug wires, and it can get bad enough to cause misfires if left unchecked. You likely won't see the oil until you pull a spark plug boot out and fling oil everywhere. This piece is fairly straightforward to replace after removing the throttle body, intake pipe, and spark plug wires. Remove it by removing the 4 oil plugs holding it in, they use a 14mm hex key or Allen wrench. If it was leaking, you should replace your spark plug wires and possibly spark plugs as well. Also, since you're already torn down this far, its not a bad idea to replace the valve cover gaskets as well, as they tend to leak a little oil with age. __________________ 1989 7MGTE R154 Targa Top White Package w/Blue Interior Driftmotion 57trim CT26, Upgraded Intercooler, 2.25" Hard Pipes, 3" Turbo Back Exhaust with Test Pipe, HKS VPC w/GM 3 bar MAP sensor, APEXi S-AFC, Walbro 255lph fuel pump, ProSport EVO Series Boost / Fuel Pressure / AFR gauges, Lotek a Pillar Gauge Pod, HKS Type 0 Turbo Timer, Eibach Lowering Springs, Tokico Illumina II TEMS struts, custom powder coated Motegi Racing TrakLite wheels

02-23-2015, 01:53 PM	#6
btwilson86 Super Moderator Join Date: May 2007 Location: Billings, Montana Posts: 1,034	If the oil is around the spark plug wires, it seeps into the wire making a poor connection to the spark plug causing the spark to short at the cylinder head and not travel to the plug, resulting in misfires and rough running. I'm not sure how a degreaser could cause a rough idle, unless a lot of it collected in one spot and is basically doing the same thing the oil was __________________ 1989 7MGTE R154 Targa Top White Package w/Blue Interior Driftmotion 57trim CT26, Upgraded Intercooler, 2.25" Hard Pipes, 3" Turbo Back Exhaust with Test Pipe, HKS VPC w/GM 3 bar MAP sensor, APEXi S-AFC, Walbro 255lph fuel pump, ProSport EVO Series Boost / Fuel Pressure / AFR gauges, Lotek a Pillar Gauge Pod, HKS Type 0 Turbo Timer, Eibach Lowering Springs, Tokico Illumina II TEMS struts, custom powder coated Motegi Racing TrakLite wheels

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02-22-2015, 05:04 AM	#2
zonian91 Stock Join Date: Feb 2015 Location: Newport News, VA Posts: 8	A little help please!

02-22-2015, 07:29 PM	#4
zonian91 Stock Join Date: Feb 2015 Location: Newport News, VA Posts: 8	Thanks a lot for responding and the advise. I'll check that out ASAP.

02-23-2015, 03:09 AM	#5
zonian91 Stock Join Date: Feb 2015 Location: Newport News, VA Posts: 8	Looks like you were right. There is a lot of oil built up underneath the distributor and there was also a lot of oil around the spark plug wires on the head. I sprayed some purple power on it to clean it off before tearing it down, but now the car is idling rough! It was running perfect before?