Laguna diesel head gasket

A colleague at work has a Renault Laguna 2.2 turbo diesel from 1997 which is passing bubbles into the radiator. He assumes it is the start of head gasket failure.

After he has lifted the head and checked the extent of the damage, how much should it cost to skim the head? Does the block ever need attention? Do these heads have a tendency to warp? Is it possible to build up the damaged area so it doesn't need as much skimming off?

Also he asked if anyone has ever tried adding a vent from the top hose to vent the gas pressure so it doesn't depress the water level in the engine?

Bill Derby Bill H Derby

Reply to
Bill H
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If the gasket has only just recently started to fail, and the engine hasn't overheated then there's a good possibility the head won't need skimming. Worth getting it checked though. A skim shouldn't cost too much, usually under £50.

I've never heard of it.

A lot of heads do if they overheat.

It would be best just getting it skimmed to avoid potential failures.

Reply to
Sandy Nuts

About 40quid tops.

If it does the bottom end is completely scrap.

Yes, often- but not if he does the HG pretty soon. If it overheats, even slightly, the head will warp.

Yes, but a 2nd hand head would be cheaper!

Bear in mind there are 3 different thicknesses of HG on this engine depending on piston protrustion- measured with a dial gauge. If you skim the head, chances are you'll need the HG which is one grade thicker.

Don't be silly.

Tim..

Reply to
Tim..

It's not that uncommon for a block to need a skim.

I'm not so sure that's the best policy. I'd rather refit an OHC head that only has a slight warp, and trust the cyl head bolts to pull it down. If it's warped a lot it's probably better to fit a good straight head, rather than have it skimmed. Mike.

Reply to
Mike G

Why? You skim blocks when blueprinting engines.

Reply to
Conor

You don't tend to blueprint diesels, & if you did the compression ratio would be outside the limits after you'd skimmed the block.

Reply to
Duncanwood

Why? A few thou won't make that much of a difference. Do you know what manufacturing tolerances are?

Reply to
Conor

Well yes, but we're talking in the context of skimming due to warpage due to overhearing.

If the cast iron block on this TD laguna has warped enough to need skimming, the bores will be scored at the least if not the whole thing seized.

Tim..

Reply to
Tim (remove obvious)

Are we? I thaught the question was whether blocks ever need attention. The answer is yes.

Other than for tuning etc, blocks are usually skimmed because of damage or rust. I've never heard of one warping due to heat. Mike.

Reply to
Mike G

You'd have to fit a thicker gasket based on measured piston protusion but it's certainly possible. I stripped and skimmed (well arranged to have skimmed) a diesel Rover 400 series for a mate after he arsed about levering the f***ing head off and scored block and head to hell and gone. After a skim of both faces we had the next to thickest gasket indicated and all was well.

Reply to
Chris Street

I have a Laguna 1.8 SOHC. Blew the head gasket big time at 80mph on the Motorway. Formula 1 stylee. Steam trail following me out the exhaust and oil pumping out the front of the head. Changed head gasket - no skimming - job done.

Reply to
gazzafield

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