2013 Silverado LTZ 5.3 (LC-9) leaking oil from head gasket? Is that possible?

Mrjack55 · September 22, 2021

The whole drivers side of the engine block is wet front to back with oil, but it's all lower (under the exhaust manifold). The valve cover gaskets are fine.

Truck has 160000 miles on it, so yes it's been well driven, but how does the head gasket leak oil and no coolant?

According to the shop I took it to, they said the UV dye showed it coming from the head gasket. Is the front cover gasket or front crank seal a more likely source?

They quoted me $3K, which seems like a lot for head gaskets. I know it's about 12hrs worth of work, but $3K? I'm not bashing the shop, as I understand the labor. I just don't have $3K.

Has anyone else had anything like this? Am I way off the mark thinking this could be something else, and not as expensive to repair?

Thanks in advance for all help/advice. Sorry for the rant. This one has me fired up.

dna9656 · September 22, 2021

Heads on Chevys used to leak oil from where the valve cover and the head met, engine oil would collect there and eventually soak any gasket you could install; you have to tighten the valve cover gasket exactly to spec (nobody looked this up) for it not to leak. This is why (since 1986 I believe) the valve covers were held in place by bolts in the center of the cover thus eliminating crush points under the bolts that were on the edge of the head that caused the leak between the cover bolts. I do not know when Chevy went to the style I have on my 06 5.3 but the seal (a very fancy kind of O ring doesn't leak as it's no where near the oil.

If the oil isn't leaking from the removable cover I think you must have a crack right under the cover's home. I think you could get that welded up if you can get it oil free. I've never seen or heard of an leak oil from the head gasket area, it's always been coolant.

swathdiver · September 22, 2021

11 hours ago, Mrjack55 said:

The whole drivers side of the engine block is wet front to back with oil, but it's all lower (under the exhaust manifold). The valve cover gaskets are fine.

Truck has 160000 miles on it, so yes it's been well driven, but how does the head gasket leak oil and no coolant?

According to the shop I took it to, they said the UV dye showed it coming from the head gasket. Is the front cover gasket or front crank seal a more likely source?

They quoted me $3K, which seems like a lot for head gaskets. I know it's about 12hrs worth of work, but $3K? I'm not bashing the shop, as I understand the labor. I just don't have $3K.

Has anyone else had anything like this? Am I way off the mark thinking this could be something else, and not as expensive to repair?

Thanks in advance for all help/advice. Sorry for the rant. This one has me fired up.

Uhh, I call BS on the shop. Does your truck have the external engine oil cooler? Even if it does not, the block off plate can also leak. Weeping or leaking power steering lines can also spray oil on the block under the manifolds.

Best I can tell, oil comes up through the cam bearings to the lifters and up through the pushrods and drains back down. Down through where, then? I would think that if the head gasket was compromised and leaking oil, your motor would not be running, at least for long.

Oilyone · March 18, 2022

OK Mrjack, don't keep us all in suspense. Where was your oil leak? My 2012 5.3 with 60K miles has developed an oil leak from somewhere near the back driver side. Oil shows up down below on the side of the engine and bell housing. Oil even drips down on the transfer case prop shaft. Had it in to the dealer yesterday and they couldn't spot the leak so put dye in the oil and want me back in 1000 miles or so. They mentioned the head gasket but I don't think that's possible. Maybe cam cover gasket, oil pressure sensor or valve timing sensor? My torque converter and flywheel and oil filter are dry. Here are some photos.