Alex Posted August 23, 2016 Share Posted August 23, 2016 My son's car: 2005 Mazda 3 / 2.3L / 120,000 Kms The problem: This car just guzzles down the oil! It's gotten to the point that he has to add 1L at every fill now! What we've done so far: Replaced PCV valve, thoroughly "cleaned" the throttle body and injectors, switched from 5w20 to 5w30, replaced the spark plugs (old ones did not look that bad!)....=no change! Other than that, the car runs very well, there are NO visible oil leaks, the exhaust appears normal, it starts up easy, and we have not experienced any loss of power. Where the F@ck is all that oil going?!? It probably needs a full top end rebuild. Where would you recommend we go? About how much does this service cost? AND...is it really worth it on this car?!? Thanks in advance guys! Quote Alex 1980 911SC Targa "turbo" - Light Blue Metallic 2007 997TT Coupe - black/black and black - now wrapped Gloss Red Metallic Link to comment
Rick Posted August 24, 2016 Share Posted August 24, 2016 (edited) Hi Alex ... Not certain how long the condition you describe has existed, so here's my first suggestion. Remove the radiator cap and inspect the condition of the coolant. If it is beige or brownish (looks like coffee with creamer added) in color, the engine has a compromised head gasket and oil is leaking into the cooling circuit. This may also present as milky coloured oil when you perform an oil change. Note: It may also be using oil in one of two common ways. #1.) Burning oil under acceleration load (not always visible from inside the car while driving) is usually related to worn piston rings. #2.) Subtle or high use of oil under off throttle deceleration conditions (also hard to see from inside the car while driving) is usually related to worn valve guides & seals. Let me know what you find. Any additional details you can think to provide will be helpful ... if the above is not your problem. Barnsey Edited August 24, 2016 by Rick Quote Link to comment
malcolm Posted August 24, 2016 Share Posted August 24, 2016 Not that many places for the oil to go: 1) on the ground from significant leak(s) 2) out the exhaust from worn or damaged engine component(s) 3) into another system such as coolant or transmission #1 is easy to check #2 check engine compression then perform a leakdown test........either test will confirm which part of the internal engine part is worn/damaged #3 check coolant as Rick describes.......if theres oil in the coolant then its another serious engine related issue. Also check the transmission fluid if the car is front wheel drive.......the engine oil may be seeping into the gearbox from a bad seal. good luck......Malcolm Quote '21 Macan GTS PDK Miami Blue/Black, 7k kms '93 928 GTS 5 speed Polar Silver/Linen, 192k kms '88 928 S4 A/T Black/Ivory, 190k kms '09 Cayenne GTS Tiptronic Nordic Gold/Black, +336k kms '88 928 S4 A/T Red/Champagne, 110k miles (US car) Link to comment
Alex Posted August 24, 2016 Author Share Posted August 24, 2016 Thanks Rick! We last performed an oil change about a month ago and the oil did not appear milky in any way. As far as the coolant, it appears to be fairly clear. I should point out that this has been an ongoing problem for the last 2 years or so, but it has been worse as of late. I suspect the problem is either #1 or #2 but one would assume that their would be a noticeable loss of power? Quote Alex 1980 911SC Targa "turbo" - Light Blue Metallic 2007 997TT Coupe - black/black and black - now wrapped Gloss Red Metallic Link to comment
Alex Posted August 24, 2016 Author Share Posted August 24, 2016 Malcolm, The Mazda 3 is a 5 speed manual and not an automatic so wouldn't that negate your point #3? Quote Alex 1980 911SC Targa "turbo" - Light Blue Metallic 2007 997TT Coupe - black/black and black - now wrapped Gloss Red Metallic Link to comment
malcolm Posted August 24, 2016 Share Posted August 24, 2016 Malcolm, The Mazda 3 is a 5 speed manual and not an automatic so wouldn't that negate your point #3? Not necessarily, if the car is front wheel drive the engine and gearbox blocks/cases will be joined with a shaft with seals between. Engine oil pressure could bypass a failed seal and leak into the gearbox. A simple check of the transmission oil level will verify. Quote '21 Macan GTS PDK Miami Blue/Black, 7k kms '93 928 GTS 5 speed Polar Silver/Linen, 192k kms '88 928 S4 A/T Black/Ivory, 190k kms '09 Cayenne GTS Tiptronic Nordic Gold/Black, +336k kms '88 928 S4 A/T Red/Champagne, 110k miles (US car) Link to comment
malcolm Posted August 24, 2016 Share Posted August 24, 2016 ........ I suspect the problem is either #1 or #2 but one would assume that their would be a noticeable loss of power? Not really; worn valve guides and seals would cause high oil consumption but the cylinders would still seal well. Quote '21 Macan GTS PDK Miami Blue/Black, 7k kms '93 928 GTS 5 speed Polar Silver/Linen, 192k kms '88 928 S4 A/T Black/Ivory, 190k kms '09 Cayenne GTS Tiptronic Nordic Gold/Black, +336k kms '88 928 S4 A/T Red/Champagne, 110k miles (US car) Link to comment
malcolm Posted August 24, 2016 Share Posted August 24, 2016 just did a quick google on this condition........it seems many other Mazda owners have the exact same issue most of whom point to the PCV valve as cause. Quote '21 Macan GTS PDK Miami Blue/Black, 7k kms '93 928 GTS 5 speed Polar Silver/Linen, 192k kms '88 928 S4 A/T Black/Ivory, 190k kms '09 Cayenne GTS Tiptronic Nordic Gold/Black, +336k kms '88 928 S4 A/T Red/Champagne, 110k miles (US car) Link to comment
Alex Posted August 24, 2016 Author Share Posted August 24, 2016 just did a quick google on this condition........it seems many other Mazda owners have the exact same issue most of whom point to the PCV valve as cause. Yes, we were aware of this. We did finally replace the PCV valve about two months ago but nothing changed. The old valve was actually still in pretty good shape. Quote Alex 1980 911SC Targa "turbo" - Light Blue Metallic 2007 997TT Coupe - black/black and black - now wrapped Gloss Red Metallic Link to comment
Alex Posted August 24, 2016 Author Share Posted August 24, 2016 Good to know! Any idea how much a shop would charge for this repair? As I mentioned, other than the oil issue, the car runs very well. It's his first car and at only about 120,000 Kms we're trying to make it last through his university years...2 to 4 more years if possible. Quote Alex 1980 911SC Targa "turbo" - Light Blue Metallic 2007 997TT Coupe - black/black and black - now wrapped Gloss Red Metallic Link to comment
malcolm Posted August 24, 2016 Share Posted August 24, 2016 Verify engine condition with a leak down test; fill the cylinder with compressed air and watch if the pressure drops over a time period. Listen for escaping air at the intake....leaking intake valve, at the exhaust manifold....leaking exhaust valve. Air leaking past the piston rings will be heard in the sump....oil dipstick tube Sent from my SM-G935W8 using Tapatalk Quote '21 Macan GTS PDK Miami Blue/Black, 7k kms '93 928 GTS 5 speed Polar Silver/Linen, 192k kms '88 928 S4 A/T Black/Ivory, 190k kms '09 Cayenne GTS Tiptronic Nordic Gold/Black, +336k kms '88 928 S4 A/T Red/Champagne, 110k miles (US car) Link to comment
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