engine leaking after changing to fully sythetic oil

[micha3l1985]

Hi, I recently changed my oil to a fully synthetic engine oil. I now have a slow oil leak coming from somewhere. I have traced it along the passenger side of the sump up to the timing chain cover then lose sight of it behind the air conditioner. Just wondering if this leak could be a result of changing to the synthetic oil. I have read the because of the mol-e-cular structure of synthetic oils they can leak past seals. I was just wondering if anyone else has experienced the same issue. Also any advice on where the oil is coming from would be appreciated. Thanks

[MTN-KAT]

I will say no. My experience is with full synthetic in a petrol engine. I use Penrite, full synthetic and have not developed a leak and my seals are an older type than yours. I have read that this may have been valid in the early days of full synthetics but the chefs err chemists have changed the recipes long ago to overcome this issue. Presuming you have used the correct diesel oil I would say it's a coincidence and maybe the leak was present before and now noticeable. You will need advice from diesel experienced users to follow up on source of leak. Good luck. I hate leaks too.

[Tanglez]

Did you change to a thinner grade as well? In the old Forester I had previous, I changed to a thinner oil and it leaked from the oil filter. changed back to the thicker and it stopped leaking.

[Goodsy]

Don't laugh but did you spill a bit while filling?
Degrease it and keep an eye on the area.

[Pauly Faulkner]

Don't laugh but did you spill a bit while filling?
Degrease it and keep an eye on the area.

I've done that on more then one occasion


Synthetic is no different from mineral in regards to leaks. If anything, a synthetic will only cause a leak over mineral if there is crap plugging up a leak and the synthetic cleans it away.

[brentw]

I once thought I had a leak on the front transfer till I looked up and realised I'd spilt a little diesel when doing the filter... Big relief that was!

[schnitzel]

I've done that on more then one occasion


Synthetic is no different from mineral in regards to leaks. If anything, a synthetic will only cause a leak over mineral if there is crap plugging up a leak and the synthetic cleans it away.

correct, give the man a beer. Synthetic oils do not cause leaks however they do clean an engine better in most cases and have been knowwn to allow an old leak which has benn plugged by gunk to to open up as it has better cleaning agents than the cheap mineral oils.

The same has higher viscosity oils dont stop leaks over thinner ones if there is a leak there oil will find it eventually unless some of the rubbish floating around in an engine blocks it.

[whitehillbillies]

Hi,
Spoke to the Penrite Tech Guy.
The only oil he recommended for my 98 Challenger, V6 3.0L with 231,000 klms, was HPR30 20/60 mineral. He also asked the area I lived, Northern NSW, SE QLD.
I was advised Not to use a synthetic based oils, in a motor that old with that many klms, as it was only designed to run on Mineral based oil !!!!
Synthetic oils, may bypass the rings causing the bores to glaze up, increasing oil consumption, and oil leaks may appear due to the cleaning properties in it.
These comments were also confirmed, by the local engine rebuilder, with nearly 40 years under his belt, with many older engine having to be rehoned, due to bore glazing, as a result of not using a mineral oil.
Penrite convert.

whitehillbillies

[MTN-KAT]

Hi,
Spoke to the Penrite Tech Guy.
The only oil he recommended for my 98 Challenger, V6 3.0L with 231,000 klms, was HPR30 20/60 mineral. He also asked the area I lived, Northern NSW, SE QLD.
I was advised Not to use a synthetic based oils, in a motor that old with that many klms, as it was only designed to run on Mineral based oil !!!!
Synthetic oils, may bypass the rings causing the bores to glaze up, increasing oil consumption, and oil leaks may appear due to the cleaning properties in it.
These comments were also confirmed, by the local engine rebuilder, with nearly 40 years under his belt, with many older engine having to be rehoned, due to bore glazing, as a result of not using a mineral oil.
Penrite convert.
whitehillbillies

Now that's interesting. Checked the Penrite lube guide and sure enuff HPR 30 a 20-60 mineral oil is recommended for the 98 Challenger 3L V6, so the tech guy stuck to the script. However, HPR10 a 15-50 full synthetic oil is recommended for my 99 NL 3.5L V6! Not much difference in these engines? I was using HPR10, but blue smoke at idle made me blu so tried HPR15 (recommended where 15-50, 20-40 or 20-50 specified) and no more blue smoke. Also figured by the time the spaghetti breaks down I will have a 15-50 oil left instead of a 15-40 when using HPR10. So far so good for me and if one believes the marketing gurus then HPR15 must be the ducks nuts for older engines.

PS: after thought had me revisit Penrite Lube Guide and search for the recommended oil for the earlier engine in NJ, NK ie 6G72 3L V6 93-97 and guess wot? HPR15, a 15-60 full synthetic oil is the recommendation. Isn't this the same engine as the 98 3L V6 Challenger?? Confirms my ducks nuts theory. And doesn't this info contradict the advice given by the Penrite tech guy above (not to use full synthetic oil in engine that old), just a tad. You see next year the guide will change the recommended HPR10 to HPR15 for my model. I'm just one step ahead of them.

[Easykill1978]

if it leaks, just showing severe wear spots...

kind of like indicators.. tho once you go synth stay synth or you may be in for a new motor or rebuild....

but to each his own.

[whitehillbillies]

Hi, 500 klms with the HPR30.
Degreased the motor after adding the oil.
The two leaking rocker covers have stopped. the two leaking camshaft seal are still dry ( just bought two new 'O' ring for replacement ) and another leak under the motor is still dry.

whitehillbillies