Jump to content
The mkiv Supra Owners Club

Small block engine trouble....


Recommended Posts

Well, i think my ultima's not too well.. Took it for a drive today, and noticed the oil pressure dropped from 2 1/2 bar to 1 bar when i pulled up to a stop after a 5 mile drive.

 

Pressure went up if i held the revs to just over 1k, but wasn't ideal. Drove home (5 mins if that) cut it off and checked it over. Seems I've lost a fair bit of oil somewhere, as although no drips, the underneath of the car had a film on it.

 

Checked the water once cooled down, and noticed it was dark and lurky, not milky - but looked dirty. - Hopeing it's not oil, but that would explain where the oil's been going and why the car's burning it.

 

Oh well, had the car two weeks and a hidden problem has occured - I guess that's why it was up for sale. Anyone want to buy a 24k lemon?

 

Hopefully it's nothing too bad - i think worse case is a head gasket - so does anyone know how much it would cost to get repaired? 5.7 v8 chevy small block. Any other damage it may of caused?

 

What checks i can do before i send it off to the garage? - i was thinking of taking out a spark plug and seeing what that looked like?

 

Thanks

 

Craig.

Link to comment
Share on other sites

If you take it to a garage they can do a compression test on the engine to ascertain if its the head gasket or not.

 

Also they can do a chemical check on the coolant i think to see if there are hydrocarbons, indicative of HG failure.

Link to comment
Share on other sites

A head gasket failure won't, per se, cause bad oil pressure. is it an electric gauge or mechanical? If electric check the pressure on a proper mechanical gauge, some senders can be very suspect. I'd pull the engine and have a look inside the bottom end if it's REALLY bad oil pressure, and not a lying sender.

Link to comment
Share on other sites

Sorry to hear that, i know off a very cheap new SBC lump sitting in the corner of a workshop that was ment for an ultima but the owner decided on a ls2 lump, its complete and looks the bizz, £1800 he wants for it, if you want it give me a pm and i will put you intouch with him, good luck with it:)

The guy builds ultimas and can install it fr you.

Edited by JamieP (see edit history)
Link to comment
Share on other sites

For an update guys -

 

Just checked the oil level and it was only just regestering on the dipstick - I then straightened the dipstick as it was curved and tried again - Hey presto - the oil is sitting dead on the MAX fill line.

 

As for the oil pressure - spoken to a few chaps on the ultima forum, and they think that the loose wire should be for the oil pressure sensor - however - they did mention that the oil i put in it as advised by someone from Le Mans was the wrong type (10-45) apparently i should of used 20-50.

 

So anyway - it's going to the garage to have all the fluids replaced brakes, engine, gearbox etc, and then i'll see what's what. I've also got two chaps who have built there own Ultima's coming over on Sat (maybe) to have a look and see if they can help.

 

God i love forums.... They make you so worried - yet so satisfyingly happy when it's all good news. - ok not good just yet - but still happier than yesterday..

Link to comment
Share on other sites

One of the best oils I have used in pushrod engines is Valvoline Racing, a low ash mineral oil with superb anti scuff properties, that helps with cam to follower wear. Being low ash it helps stop det, too, as the huge piston and valve areas are less likely to suffer glowing particulates form oil ash formation.

 

 

I would be amazed if your oil pressure problems are oil grade related, absolutely amazed. If it has an oil cooler you should use a filter with an anti drain back valve within it, and you need to be sure the line and fitting sizes are adequate for the oil flow these engines generate. They can also loose substantial oil pressure if the oft neglected cam bearings aren't changed, as they tend to be left as few people have, or can be bothered to make, suitable mandrels to remove the old and fit the new.

 

Once out it's a very basic and easy engine to fiddle with, at stock performance and mild tune levels, it is often better to fix what you have rather than risk something used and unknown.

 

Do a leakdown test, a compression test, a gasses in coolant test and a check the oil pressure hot on a master gauge straight off the main oil gallery. It's not dry sumped, is it???

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.