smitty2919

First LT1 car I have owned. Have had it for 2 years or so now and has leaked since I got it. Raced 2 autocross seasons on it as well as DD. I finally got annoyed with it marking it's territory everywhere it went and oils spots in my garage.

So 4 weeks ago I went ahead and replaced the Opti drive seal and crank seal...still leaked, but I bet the Opti seal was giving out a little.

Then I decided tackle the rear main seal assuming that was the issue...ripped everything out, new TOB, new pilot bearing, new rear main seal, new oil pan drain plug, new FW bolts, resealed the Low Oil sensor, oil change, trans fluid change put it all back together feeling pretty confident...still leaked after driving it for only 5 min....effffff YOUUUUU!!!

Looked around and noticed oil on starter, oil path dripping down the edge of bellhousing so I knew it was coming from somewhere higher than rear main seal. I found a thin film of fresh oil on TOP of the bellhousing...hmm intake leak?

NOW it's personal...2 nights ago I ripped the intake off and valve covers. New Intake gaskets and VC gaskets went in last night. Torqued intake back on and should finish it up tonight or tomorrow.

For only driving it a couple of miles and leaking as much as it did to see drops on the floor and knowing it started up top and worked it's way to the bottom of the bell housing tells me it must be a significant leak.

The journey continues...

Jaxem

iTrader: (3)

What did you use to seal up the front/back of the intake? I had a similar leak that turned out to be the rear of the intake. A thick bread of copper silicone left for a couple days fixed it for good (so far)

ahritchie

iTrader: (1)

Did you check the oil pressure sensor fittings that screw in to the back of the intake? I had leaks from the fittings before. Or it could just be the infamous back of the intake leak, maybe you didn't use enough RTV or let it dry long enough?

Might want to get some florescent dye like the tracerline kit if your serious about finding out where it's coming from. Makes it easier to know your not replacing the wrong gaskets.

smitty2919

Friend that works at a speed shop highly recommended Permatex Gear Oil silicone gasket maker. It is grey similar to the OEM stuff.

I did look at the oil pressure sender unit. I removed it, cleaned the threads and resealed everything with copper RTV.

If it still leaks, I don't know what other gaskets to replace LOL.

BTC

The water pump drive seal is a fairly common leak, and it's above the opti seal in the timing chain cover. Whether or not it could explain where you are seeing oil, I'm not sure. I suspect what you were seeing is from the rear of the intake.

senicalj4579

iTrader: (41)

IDK what mods you have but hows your crankcase pressure? Too much can cause leaks. Mines been leaking ever since the hci build and couldn't figure out why but now I have an idea. I'm going to explore relieving that excess pressure.

smitty2919

WP drive seal was OK when I did the Opti seal and crank seal. It's a stock motor with full exhaust and a tune so I wouldn't suspect excess crankcase pressure.

Having a 21 year old car and original silicone on the intake would be a good bet lol.

Should have everything back together tonight and see how it goes. I had intake gaskets for a long time sitting around so I had planned on doing them at some point.

If it still leaks, I may try that dye to track down the leak.

BALLSS

Smitty

you have been front, back & top of motor chasing a leak.

>>>>I would stop throwing parts at it and first confirm "source" of leak. oil dye and a black light are very helpful in this.

Might want to clean as much of the motor & suspension as you can to remove what oil residue likely exists from whatever the leak(s) source may be first

the leak down bell housing is likely rear intake or valve cover. People have their RTV preference, I use Permatex Black Ultra.

For problematic leaks on rear of intake "dimpling" the rear block & intake with a punch has proved successful for problematic intake sealing. Let the RTV cure overnight before starting motor

smitty2919

I would tend to agree about not throwing parts at it, but it was a good thing I did rear main seal to be able to clean the whole car and trans.

The intake was next logical thing, again allowed me to clean it. Intake seal may be promising, but now I'm also seeing a leak from the Low Oil sensor itself. Not the threads into the pan (because I sealed that), but the oil is leaking THROUGH the sensor between the inner guts and the outer metal "nut".

Man this thing is a fickle beast lol.

Jaxem

iTrader: (3)

Yeah, mine was starting to seep from the sensor, so i put a plug in that hole and tied the wires together...i check the oil pretty frequently, so no real loss

smitty2919

Do you know what size plug you bought for this and where you got it??? I thought about doing this last night.

Jaxem

iTrader: (3)

It was 20mm x 1.5, many parts stores have them with their oil drain plugs. Got mine at o Reilly's

smitty2919

Splendid, thanks a lot.

ahritchie

iTrader: (1)

Why not do it right and just replace the sensor?? They cost around $25. Maybe it's just me but I kinda like having an actual working oil pressure gauge.

That kinda tight wad half *** "repair" is oh so typical of certain LT1 owners...

BTC

I don't believe that sensor has anything to do with oil pressure readings. I believe they are referring to the low oil level sensor that's in the oil pan.

smitty2919

Read the comments...I'm plugging the "low oil level" sensor. Nothing to do with the oil pressure sensor. Plus I already have a much better aftermarket oil pressure sensor IF I was to plug the OEM pressure sensor.

I would replace the sensor, but the replacement ones are plastic body and threads. I'm not a fan of putting plastic that close to the headers and numerous heat cycles for it to crack and become brittle over time. Again, that's why they invented oil dipstick tubes...I check oil on a monthly basis.

Typical mullet LT1 owners can't read dem durr sentences.

Good news is that the intake fix has greatly reduced the oil leak. Have driven the car 2 days now and no spots on the ground over night.