dschlact

Hi - My 88 K5 Blazer with GMC 350 Motor has a small oil leak. It appears to be coming from the rear of the motor and dripping down the back side...it eventually drips onto the exhaust pipe and I get the smell of freshly burnt oil

Any suggestions on things to check before taking it into the shop? I would like to rule out the simple/DIY checks before spending too much $ getting it checked out.

Thanks,
Dave

maxxman04

could be oil pan, rear main seal, backside of valve cover. it's possible it's front seal on trans too, but that'll be a reddish color.

dschlact

Pretty sure it is coming from higher up on the engine than the oil pan...how do I check the rear main seal, valve cover and trans seal? I am 99.99% sure it is motor oil, not trans fluid though.

I appreciate the advice.

Dave

maxxman04

rear main will drip down the backside of oil pan, valve covers will drip down the heads. if fluid isn't reddish, then wouldn't worry about trans. may just need to try to trace the leak to origin. it's also possible it's leaking from intake manifold, backside of it somewhere around distributor.

Terry Neff

There is a company who's name escapes me at the moment that you buy a dye that is safe to put in the oil.You clean the area real good and use a black light to trace the leak.The kit with the black light is pretty cheap.After you find the leak,you change the oil and filter.

frickenbored

its a 350, I've never seen one that didnt leak from some where.

72c10gunn

it could be coming from the back of the intake from the liffter valley, it usually drips down the back of the trans if thats the case

dschlact

how critical is it to find and repair the leak? If I continue to monitor the oil level am I safe or do I run the risk of blowing something?

therewolf

Hi dschlact,

Welcome to the Chevy Forums.

I'd keep a close eye on it, and a couple of bottles of with you. But it would probably take quite a bit of driving to burn up the engine, if you don't get careless.

In many cases, the PCV valve clogs, which forces the valve covers to leak.

If you check around the rear of the valve cover and find a leak, you probably want to replace the valve cover gasket, and the PCV valve and breather.

Try to remember who does that oil dye thing, that sounds like the coolest stuff since Zyglo.

blazen fool

probably the oil sending unit notorios for leaking i always pull it and use a mechanicle