Oilly question ?

Discussion in 'Chevy C/K Truck Forum' started by JTWard, Apr 21, 2014.

  1. JTWard

    JTWard Rockstar 3 Years 500 Posts

    What is the best route to go from converting a 5W/30 conventional oil to a 5W/30 synthetic oil ? I've always heard that synthetic will just start a oil leak if it's been run on conventional motor oil. My 1990 305 V8 has always been fed 5W/30 conventional oil and I'm wondering if a switch to synthetic would be beneficial ? I have 112.096 miles on my truck. :happy:
  2. garyj044

    garyj044 New Member

    I use Castrol high mileage in mine, and have for years. 184000 runs great 1997 K2500 7.4
  3. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    I only use synthetic.
    When I buy a vehicle, I change the oil to synthetic during the first week. I have never had a leak and never regretted changing to synthetic.
  4. kennythewelder

    kennythewelder Rockstar 3 Years 1000 Posts

    Yes, synthetic would be beneficial. To switch, it is a simple as just doing an oil change. As for Castrol, I wouldn't use it as chain oil on a chain saw. I pulled my intake manifold several years ago to repair an oil leak. My truck had Castrol GTX all of its life. I could not believe the waxy gunk build up inside the lifter valley. It was nasty to say the least. It took my about 2 hours to clean it all out. I now use Valvoline conventional oil. I change my oil and filter every 3000 miles, and always have. I have almost 210000 miles on my truck now. It doesn't burn any oil at all, and I run the truck hard. LOL now back to synthetic, it penetrates the metal. I have tried to weld steel that has had synthetic oil on it or inside it and it welds like garbage. It is next to imposable to get synthetic oil off of the metal. I really think that the most important thing is, regular oil and filter changes.
    summitwhite11 likes this.
  5. Chesters

    Chesters Well-Known Member 2 Years ROTM Winner Gold Member 1000 Posts

    Kenny , I understand your bias to good old crude. But if you live where the temps drop to 20- it might make alot more sense to you and possibly change your mind. That one day you went out and heard that horrible knock they make when the oil can't move. Just sayin:eek:
  6. kennythewelder

    kennythewelder Rockstar 3 Years 1000 Posts

    I hope this doesn't sound offensive, it is not meant that way at all. I have nothing bad to say about synthetic oil. I think it is very good. Better than conventional oil by all means. I just have a real issue with Castrol, even there synthetic. I feel ripped off by there hype. I thought it was good oil, but after what I saw in my engine, I wouldn't poor it on an ant pile to kill them with. There are some things I would never ever buy or use, and Castrol is at the top of my list. I wouldn't use Quaker State either. Or Fram filters. LOL or FORDs but I think you know that already, how I feel about FORDs. If what happened to your engine would have happened to mine, I think I would pull down the top of the engine and see If I could figure out why it happened. Bottom line, you will have a better truck when it is repaired. I know what it is like to be on a budget, and what it is like when the unexpected happens. I wish you the best in your efforts to repair your ride.
    Last edited: Apr 17, 2015
    Chesters likes this.
  7. kennythewelder

    kennythewelder Rockstar 3 Years 1000 Posts

    up dated my post please re read Chester
  8. poncho62

    poncho62 Active Member 2 Years 100 Posts

    I have heard the sludge stories about Quaker State and Pennzoil too. I figure oil is oil, but who knows.....Recently, I have been using the Canadian Tire house brand synthetic. It seems to work well for me. My truck has been using a bit of oil lately and I get a slight tick at startup.....I am going to try a 10w3o instead of 5w30 this summer.....I dont think it will help, but we will see
  9. Chesters

    Chesters Well-Known Member 2 Years ROTM Winner Gold Member 1000 Posts

    Thanks Kenny and I understood from the get go. Just up north synthetic is the way to go IMO. As far as the truck, it is going to have to wait, I might be able to make room for it in the shop for a winter project but right now it's summer or near it. Time to keep what I have running and get that garden from hell in here soon.

    The pipes sound great on the 2500 hopefully she holds up for another 90,000

    @JTWard How's those breaks buddy????

    Poncho I do switch over to 10W30 on my high mileage vehicles in the summer time. Again just feel they get better protection when the heat is on!! I change oil every 3 months not milage dependant, I would be lucky to get 3000 on a qtr.

    Kenny one of the guys I work with has one of the newer Charger RT's Hemi He says he figures he is right near the 600HP area with the mods he has done
  10. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    I've used that synthetic as well, seems to work well.

    I don't worry about a little tick at start-up, I think every GM V8 I have ever owned ticked at start-up.

    Look up the Marvel Mystery oil threads, it seems to do a good job cleaning lifters.

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