Minivan got engine rebuilt but lacks power...this normal?

Discussion in 'Off Topic [BG]' started by rabid_granny, Feb 25, 2003.

  1. Well, we couldn't renew our family minivan's insurance because it failed our provincial air emissions test. It is an old 1988 Plymouth Grand Voyager Limited Edition and I guess the engine's seals were faulty.

    My dad had our minivan's engine rebuilt last week. The engine runs smoother now but lacks power - no pickup at all. It struggles uphill even though it is a 6 cylinder engine.

    The mechanic said that it is because the engine is new and hasn't been broken in. But we can't help but wonder if it is because he did a bad job.

    Is it normal for a rebuilt engine to lack power at first? How long before the engine gets back to normal?
  2. No expert here, but, if it's that noticeable I'd think that something's amiss.

    Where's Mike N? :)

  3. Mike N

    Mike N Missing the old TB

    Jan 28, 2001
    New York
    No, its not normal. Which V6 is it, the 3.0 or 3.3?(Im figuring its the 3.0) Also, did it run ok before being rebuilt? Check the basics like ignition timing and fuel pressure. Also, check to see that the exhaust isnt restricted(the old "potato in the tailpipe" routine), and that all vac hoses are hooked up correctly.

    My gut feel(when I read your post) is that the timing belt is installed a few teeth off, which would certainly result in poor performance.

    Good luck, and keep us posted.
  4. Well rabidgranny, a 3.0-3.3L V6 with little horsepower and torque (Which I believe those Voyagers had; Chances are, unless it is about 80L of displacement, an American car has no power :D JUST KIDDING!!!) pushing a relatively heavy vehicle is not going to have any pep up a hill in the first place, unless you REALLY push the engine to about 5000-6000 rpm.

    I wouldn't be suprised in the least if it was the timing belt.

    But now I have a question for Mike N: What exactly is that mechanic's logic? I mean, why, necessarily, does an engine need to be "broken in"? Or am I really missing something....
  5. Mike N

    Mike N Missing the old TB

    Jan 28, 2001
    New York
    Usually you should be easy on a new engine for the first 500 or so miles so the rings have a chance to seat against the cylinder wall, and the lifters/camshaft have a chance to establish a good contact point with each other. After 500 miles, change the oil and filter and have fun.

    Performance shouldnt be any worse before the break in mileage is reached.

    Ironically, our race motors receive virtually no break in before being put on the dyno. We put them on the dyno, run them for 20 minutes, change the oil and filter, then let them rip.
  6. Trevorus


    Oct 18, 2002
    Urbana, IL
    Yeah, be very easy on the engine for a bit. Emission controls rob power anyways. And remember, it's a minivan! They are NOT, I repeat, NOT known for power. It's not a V8 Camaro with a 350. Anyways, be careful. Anything goes wrong, give the mechanic heck for it.
  7. I was totally thinking that when I wrote the post.

    I wasn't looking for the minivan to be a rocket but it seems to be struggling uphills more than before. It was burning oil before so that's why we had the engine rebuilt - otherwise, it's rock solid.

    I didn't mention this before but my neighbour (who is an engineer) tweaked the timing yesterday and it was running better but still not the same. I'm hoping it is an adjustment problem and not an error in the rebuilding process.
  8. Josh Ryan

    Josh Ryan - that dog won't hunt, Monsignor. Staff Member Supporting Member

    Mar 24, 2001
    Tweaking the timing could help, but I think the actual timing belt itself needs to be adjusted. Tweaking the timing will not solve the underlying problem if the belt is off by a couple of teeth as Mike N. said.

    A v6 mini van like that should not struggle up hills. That is not normal.
  9. Mike N

    Mike N Missing the old TB

    Jan 28, 2001
    New York
    What was the extent of the rebuild?(Im still figuring this is the 3.0 btw). Did they have the entire engine out of the van, or just put a set of reman cyl heads on it?(3.0's have a nasty habit of having valve guide problems, and they burn an incredible amount of oil due to this). Im still thinking the timing belt may be off a tooth or two.
  10. odie

    odie Supporting Member

    Hey Mike, Ive always wanted to ask. What is the big problem if an engine burns oil. Other than the fact that it maybe a sign of a problem. In the case of the 3.0, it is a common thing. So does it create a problem?
  11. malthumb


    Mar 25, 2001
    The Motor City
    I like Mike N's suggestions. One other thing to think about, though, is breathing. Remember that an engine is basically a big ole air pump. The more efficiently it pumps air the better it performs. Usually rebuilders put the customer's top end (intake manifold, fuel injection system, air cleaners and emission control elements) back on the replacement engine or rebuilt engine. If there were any issues in reassembling the top end poor breathing could result. That's the air in side.

    On the air out side, if the engine was a used or remanufactured engine, did the rebuilder use your exhaust manifolds, catalytic converter(s) and exhaust pipes or those from the source of the rebuild? Exhaust restriction will rob an engine of performance. Think potato in tailpipe. If you've ever done that prank you know what I'm talking about.

    Just a few more things to hunt down as you try to get a handle on your low power situation.


  12. I think there should be a "Cars" section of Talkbass, with Mike N as the moderator. ;)
  13. Mike N

    Mike N Missing the old TB

    Jan 28, 2001
    New York
    Depends how much youre burning. If its gotten to the point of fouling spark plugs and causing a misfire, then its a problem. If its just a puff of blue smoke here and there,(other than air pollution) its no big deal.

    If an engine uses a quart of oil every 1000 miles thats considered ok. If youre using a quart every 100 miles theres a problem.
  14. Mike N

    Mike N Missing the old TB

    Jan 28, 2001
    New York
    How much does it pay? Do I get paid vacations, 401K etc?:D
  15. I wasn't involved in the rebuilding in anyway but I believe the entire engine was removed and rebuilt using an "engine rebuilding" kit for our minivan. I forgot to check which model it is, will get back to you shortly...

  16. No Mike, you get one gallon of nitromethane and one full set of racing slicks per year :D
  17. Mike N

    Mike N Missing the old TB

    Jan 28, 2001
    New York
    Gonna need more than 1 gallon. Make it a 55 gallon drum and we can talk............:D
  18. I don't know if you had the rebuild done at a reputable shop, but a guy over here in Holland crashed his V-max after they fixed his engine. Turned out he'd been driving with his cams 180 degrees out of sync for 2 years. Power nearly doubled after they fixed it and he wasn't quite ready for that...

    Cheers Rody
  19. Unfortunately, we didn't. My dad went with a mechanic based on a friend's referral. The guy rebuilt the engine for about $1800 - the Chrysler dealership wanted $4000.

    Yeah, I'm a little worried that the guy had a serious error...
  20. Gonna need more than 1 gallon. Make it a 55 gallon drum and we can talk............

    Hehe.....not on my budget Mike....Let's find someone willing to do a deal....:D :eek:

    (Mafia voice)

    Where's Vinnie's money? Answer, or you'll get it BAD!

    (end Mafia voice)